In some of Paul's letters he has long lists of sins to be avoided, and you can easily line up the sins with the Ten Commandments. Two example passages:

Rom. 1:28-31. And even as they did not like to retain God in their knowledge, God gave them over to a debased mind, to do those things which are not fitting; 29 being filled with all unrighteousness, sexual immorality, wickedness, covetousness, maliciousness; full of envy, murder, strife, deceit, evil-mindedness; they are whisperers, 30 backbiters, haters of God, violent, proud, boasters, inventors of evil things, disobedient to parents, 31 undiscerning, untrustworthy, unloving, unforgiving, unmerciful . . .

And:

Col. 3:5, 8-9. Therefore put to death your members which are on the earth: fornication, uncleanness, passion, evil desire, and covetousness, which is idolatry. . . . 8 But now you yourselves are to put off all these: anger, wrath, malice, blasphemy, filthy language out of your mouth. 9 Do not lie to one another, since you have put off the old man with his deeds . . .

If Paul can tell Christians that they ought not to do these things, then it seems obvious to me that the law is still binding on Christians. If someone says the law is not binding, then ask if it's okay to lie and murder . . . I think the answer's obvious!

Hope this helps!

__________________
Casey Bessette
Westminster OPC • West Suburbs of Chicago • My Blog: Paradise Regained

"It is part of the calling of the ekklesia to learn to know the love of Christ that surpasses all knowledge and also to make known within the world of science 'the manifold wisdom of God' in order that the final end of theology, as of all things, may be that the name of the Lord is glorified. Theology and dogmatics, too, exist for the Lord's sake." — Herman Bavinck, Reformed Dogmatics, vol. 1, p. 46