Do the Ten Commandments continue to apply to Christians in today's society? Specifically, are we still required to keep the Sabbath (the seventh day, Saturday)? In the Gospels, Jesus kept the Sabbath, and after his death the disciples kept it also, but today Christians do not, by and large. If the Sabbath command no longer exists, who abolished it? What about passages like James 2:10-12, which suggest that the Ten Commandments should be kept? If they don't need to be, why are we instructed not to kill, steal, commit adultery, etc.?This is a great question, and is much bigger than even the issue you raised. Here's the big question: Does the Mosaic Law still apply to Christians today? Is the Old Testament still applicable to the Christian (in whole or in part), and if not, why? A complete answer to this will need to argue for either (1) a connection between the Old and New Testaments that minimizes the differences between (for example) Israel and the Church, or (2) a disjunction between the Old and New Testaments that nonetheless explains the obvious relevance of the Old Testament to the New Testament authors (and to Jesus). Hopefully this makes sense. Clearly, there are some serious differences between the OT (Old Testament) and the NT. We no longer have sacrifices, a temple, the levitical priesthood, laws of purity, circumcision, and so on. Unlike believers in the OT, we now have the revelation of Jesus Christ, the indwelling Holy Spirit, and the priesthood of all believers. But there are also similarities. We still have a chosen people of God, the same Lord, and salvation based on faith (see Gen. 15:6 compared with Romans 4:3-5). How does one explain these elements of continuity and difference? An answer to your question about the Sabbath will directly assume some explanation for this bigger question.
I have a particular view on this, but to discuss it here would take us far afield. I will post something to the Theological Questions section about this in the near future, under the heading of "Dispensationalism." I will try to give you a biblically-based answer to your question without appealing to any theological systems, but again, a complete answer would include some mention of these.
So here's my approach. I will begin with the Sabbath issue, and then conclude with a discussion of the relevance of the law for Christians.
The question of keeping the Sabbath is interesting, since the Church has not widely observed the seventh day (Saturday) since the 1st century. By the 4th century the Catholic Church had begun to imbue the Lord's Day (Sunday) with some of the characteristics of the Sabbath, but literal observance of the Sabbath day has not been part of church tradition (except for some isolated sects like the Seventh Day Adventists, or cults like the Jehovah's Witnesses) for 19 centuries. This doesn't mean we shouldn't observe the day (it's possible that the church has been wrong about this for 1900 years), but there are obviously some reasons why this command has been ignored. The larger reasons will come up in the next section, but the rationale given is usually (1) the OT law no longer applies any more, in any form, to the church, or (2) the Sabbath command is still kept, but not literally; it is kept spiritually (symbolically) in the church's worship of Christ on Sunday. I will cover these in part III, since they relate to bigger issues than just the Sabbath, but in either case there is agreement that the Sabbath does not have to be literally observed.
You point out that Jesus kept the Sabbath, and imply that because He kept it, all Christians should keep it. There is general agreement that Jesus kept the Sabbath, but He should not be considered the model for our behavior in this regard. Jesus (as God) is entitled to work; the Sabbath is for creatures, not the Creator. Jesus points this out in His defense in John 5:
And for this reason the Jews were persecuting Jesus, because He was doing these things on the Sabbath. But He answered them, "My Father is working until now, and I Myself am working." For this cause therefore the Jews were seeking all the more to kill Him, because He not only was breaking the Sabbath, but also was calling God His own Father, making Himself equal with God. (John 5:16-18; NASB)
So Jesus' observance (or non-observance) really doesn't say anything about our duty, as Christians, to follow the Sabbath. Moreover, Jesus was a Jew (under the law), as were the Twelve disciples, and even if we argue that they were required to keep the law prior to the crucifixion, it does not follow that Christians (especially those who are not Jewish) need keep it after what happened on the cross. Note that Jesus never tells anyone to observe the Sabbath, much less does He instruct His disciples to observe it, nor does any writer in the New Testament instruct anyone to keep it.
You claim that after Jesus' death the disciples kept the Sabbath, but if you check Acts you will never find a single instance where a Christian keeps the Sabbath. The only references in Acts are to Paul's use of the synagogue on the Sabbath to evangelize Jews (Acts 13:14, 42, 44; 16:13; 18:4). In fact, the Sabbath is only specifically mentioned one time in Paul's writings, and that is Col 2:16:
Therefore let no one act as your judge in regard to food or drink or in respect to a festival or a new moon or a Sabbath day—things which are a mere shadow of what is to come; but the substance belongs to Christ. (Col 2:16-17; NASB)
In this passage, Paul is telling the Colossians not to let anyone condemn them for failure to observe the Sabbath or any other Jewish holidays, since these things are not significant (they are shadows, or symbols, of a truth found in Christ). There is only one other place where the Sabbath is mentioned in the New Testament at all, and that's in Hebrews 4. In that passage, the Sabbath is understood to be symbolic of the afterlife (as a place of rest). This implies that the Sabbath has no literal validity for the church, under the new covenant (especially in the argument of Hebrews, which states that the covenant of the law has been made obsolete by the new covenant in Christ; see Heb 8:13).
I should mention one other passage in Paul which refutes the idea of keeping the Sabbath—Gal 4:10. Paul doesn't specifically mention the Sabbath there, but he does criticize observing "days," and in the context of Galatians (which is an attack on Judaizing practices), this must refer to Jewish holy days, like the Sabbath:
But now that you have come to know God, or rather to be known by God, how is it that you turn back again to the weak and worthless elemental things, to which you desire to be enslaved all over again? You observe days and months and seasons and years. I fear for you, that perhaps I have labored over you in vain. (Gal 4:9-11; NASB)
In conclusion, this is why the church has not continued to observe the Sabbath (at least, not literally, though some sections of Christianity do claim to observe it spiritually on Sunday). I have to concur; Paul and the author of Hebrews imply strongly that Sabbath observance was for Israel, not for the church. But this only touches on the larger issue of how the law relates to Christians. Are we supposed to keep the law? How can we dispense with the Sabbath, and not dispense with the rest of the law? (Or how, in James 2:10-12, which you point out, can we observe part of the law and not the whole?) Do any of the ten commandments still apply to us, then? Why some and not others? This forms the topic of the next section.
I want to emphasize something that may not be immediately obvious; namely, the difference between the character of scripture as God's word, and the application of scripture as God's revealed will. Just because God has spoken authoritatively to specific people in the pages of scripture does not mean that, in the very same way, He speaks to you, the modern reader. This is an intuitive point, hopefully. For instance, Paul writes to the Corinthian church about women needing to have their heads covered when they pray and prophesy in the assembly (1 Corinthians 9), but it is understood that women today, in the American church, do not need to wear hats or veils (or wear their hair bound up, depending on how you interpret this passage). There is a principle underneath the contingent situation in Corinth that continues to apply, but the specifics do not.
In more general terms, I would point out that not all scripture is equally applicable to all people in all times. Passages which express a husband's obligation to his wife, for instance, do not apply to single people. Passages which express a pastor's obligation to his "flock" only apply to teachers in the church. And so on. When you combine this with my earlier observation that cultural differences force us to reject certain specific applications in scripture (like women having their heads covered), it is clear that you cannot automatically take any passage from the Bible, especially one that is directed into a specific cultural situation and a specific group of people, and assume it must apply to all people today just as it did centuries (or millenia) ago to specific people.
I make this distinction because of passages like Matt 5:17-18, where Jesus states that He did not come to abolish the law, but to fulfill it. Understand that the OT is still God's word regardless of whether it applies literally to the church today. It was God's inspired word to the Israelites, and it continues to hold good principles which apply to Christians today. In this sense, it is not abolished under the new covenant in Christ. But I would argue very strongly that the commands given to the nation of Israel do not apply specifically to the church. This includes the specifics of the ten commandments. This is the larger reason I mentioned behind the more specific issue of the Sabbath law. Let me give you some proofs of this, and then I'll respond to some passages that seem to imply that parts of the OT are still in effect.
I'll focus on the apostle Paul, even though the argument of Hebrews (esp. Hebrews 8-10) rests on the idea that the covenant of the law has passed away. My particular expertise is in Paul, especially Romans and Galatians, and especially focused on the issue of Paul's view of the law. (Note the articles posted in the resources section of my web site.) So I will offer a few passages here out of context, but I could discuss the context more fully if you are not convinced. Let's begin in 2 Corinthians:
Not that we are adequate in ourselves to consider anything as coming from ourselves, but our adequacy is from God, who also made us adequate as servants of a new covenant, not of the letter, but of the Spirit; for the letter kills, but the Spirit gives life. But if the ministry of death, in letters engraved on stones, came with glory, so that the sons of Israel could not look intently at the face of Moses because of the glory of his face, fading as it was, how shall the ministry of the Spirit fail to be even more with glory? For if the ministry of condemnation has glory, much more does the ministry of righteousness abound in glory. For indeed what had glory, in this case has no glory on account of the glory that surpasses it. For if that which fades away was with glory, much more that which remains is in glory. Having therefore such a hope, we use great boldness in our speech, and are not as Moses, who used to put a veil over his face that the sons of Israel might not look intently at the end of what was fading away. (2 Cor 3:5-13; NASB)
In 2 Cor 3:5-13, Paul not only contrasts the Mosaic covenant (the covenant "of the letter," engraved on stones) with the new covenant in Christ (the covenant "of the Spirit") as life and death, but he makes it clear that the covenant of the letter is surpassed by the covenant of the Spirit because the covenant of the letter was temporary. The fading of the glory from Moses' face is understood by Paul to be symbolic of the temporary and provisional nature of the law, which ultimately comes to an "end" (v. 13). If there is any doubt about what "law" means, Paul at least understands that it refers to the ten commandments, since he equates the Mosaic covenant with "letters engraved on stones."
Observe also the following passages, which all contain the idea that (1) the law is part of a previous age, before the cross, and is connected with the power of sin, (2) the Christian has identified with Christ in His death and resurrection, and since Christ has died to sin and the law, so has the Christian, and (3) since the Christian is freed from the power of sin (and thus the law), we now operate as citizens of a new age, characterized by the Holy Spirit (and also identified with grace and life):
For sin shall not be master over you, for you are not under law, but under grace. (Rom 6:14)
Therefore, my brethren, you also were made to die to the Law through the body of Christ, that you might be joined to another, to Him who was raised from the dead, that we might bear fruit for God. For while we were in the flesh, the sinful passions, which were aroused by the Law, were at work in the members of our body to bear fruit for death. But now we have been released from the Law, having died to that by which we were bound, so that we serve in newness of the Spirit and not in oldness of the letter. (Rom 7:4-6)
For if I rebuild what I have once destroyed, I prove myself to be a transgressor. For through the Law I died to the Law, that I might live to God. (Gal 2:18-19)
But the Scripture has shut up all men under sin, that the promise by faith in Jesus Christ might be given to those who believe. But before faith came, we were kept in custody under the law, being shut up to the faith which was later to be revealed. Therefore the Law has become our tutor to lead us to Christ, that we may be justified by faith. But now that faith has come, we are no longer under a tutor. (Gal 3:22-25)
For Christ is the end of the law for righteousness to everyone who believes. (Rom 10:4).
All of these passages teach the same idea—that the law (while a good and holy thing) was nonetheless used by the power of sin to condemn the Israelites and expose their need for the righteousness which comes by faith. Since we now have reached this righteousness, we no longer need the law. In fact, to put oneself under the law is, for Paul, to submit oneself to the power of sin. The context of all these arguments is located in Paul's struggle with Judaizers—people who believe that Gentile Christians should become circumcised and thereby identify with Israel as God's chosen people. Paul rejects this, and offers the passages I have cited as arguments for why Christians should not come under the law in any respect.
These passages also explain why Jesus' observance of the law (or the disciples' before the time of the crucifixion) cannot be used to argue that Christians should keep the law. These people were Jews, under the old covenant. They were under the law; we are not. It is not until Acts, after Jesus' resurrection, that keeping the law becomes superfluous.
Now let me mention some of the arguments on the other side. First, some people argue that Paul is not against the law (or the ten commandments), but rather the principle of legalism (which is understood to be the idea that you can earn salvation through good deeds). So he is not arguing that the law no longer applies to us, but simply that the law cannot be used to gain salvation. A second argument (used in connection with this) rests on those places in the New Testament where the ten commandments are seemingly applied to Christians. For example, Paul quotes several of the ten commandments in Rom 13:9, as does James in James 2:10-12 (which you mention in your question).
On the first argument, let me point out that Paul never defines, expresses, or attacks the idea of legalism anywhere in his letters. Even if Paul thought that that was the error involved in the Judaizers' thinking (and I don't think it was, but I can't go into that here), he does not refute them by saying, "Yes, it's alright to be under the law, but just don't think you can be saved by doing good things." He refutes them by arguing that it is not alright to be under the law at all, that the law no longer applies to the Christian because it is a feature of the old age. When Christ died, He died to the law and all that went with it (sin and death). So the problem with the law is not that it is inherently bad, but that (1) it no longer applies to the church, since Christians have moved into a new era of the Spirit, and (2) it was used to enslave the Israelites by the power of sin, and so needed to be superceded by the Spirit anyway. If Paul wanted to attack a way of thinking about the law (i.e., "legalism") instead of the law itself, then why does he never explain this? Paul's problem with the law is not that it causes legalism, but that it causes us to sin all the more, and gives us no way to achieve victory (see Rom 7:4-6, above).
The second argument is about places in the NT where the ten commandments are cited positively, and seem to be applied to the Christian. If Paul mentions the ten commandments, then isn't the law at least partially in effect? What I want to stress, in response to this, is that the OT does not cease to contain truth just because it is not specifically applied to the church. The OT is still true. But murder is not a sin because it is in the ten commandments; murder is a sin because it contradicts God's holy character and the essential nature of human beings. By saying the ten commandments no longer apply to the church we are not saying that murder is no longer a sin. The essence of the law (i.e., God's will and holy character) is carried over into the new covenant, even though the letter of the law (i.e., the particular commands given to Israel) is not.
About James 2 and Romans 13 particularly, let me point out that in neither case do Paul or James say that we should obey the Mosaic law. They do not say that anyone should keep the ten commandments. What they both say (in amazing agreement) is that the entire law is fulfilled by the principle of love, and they cite some of the commandments in connection with this:
If, however, you are fulfilling the royal law, according to the Scripture, "You shall love your neighbor as yourself," you are doing well. (James 2:8)
Owe nothing to anyone except to love one another; for he who loves his neighbor has fulfilled the law. For this, "You shall not commit adultery, You shall not murder, You shall not steal, You shall not covet," and if there is any other commandment, it is summed up in this saying, "You shall love your neighbor as yourself." Love does no wrong to a neighbor; love therefore is the fulfillment of the law. (Rom 13:8-10; NASB)
In other words, when James and Paul say that love is the fulfillment of the law, they are both implying that the law is not literally required of Christians. If Christians love one another, they have fulfilled the law even though they have not kept it literally. If Christians don't love one another, it's as though they have broken the whole law.
The Sabbath command is no longer enjoined of the Christian community for the same reason that circumcision is not: the law of Moses no longer applies literally (specifically) to the church. This is not only clear by the passages that refer to the Sabbath in the NT, but also by the passages which refer to the law as part of the old covenant that is superceded by Christ. Christians are not required to keep the specifics of the law (the letter of the law), but there is still truth in the law which applies spiritually and morally to people in all times and places.