Philip Johnson sounds a little like Martin Luther in his Independence Day post titled, "Real Liberty." He shows that Christian Liberty is different than Antinomianism.
First, our liberty in Christ is a freedom from the yoke of sin.
Liberty in Christ is not a freedom from spiritual responsibility. It is certainly not any kind of moral autonomy. It is not a release from the divine standard of righteousness. It does not mean we are discharged from our duty to obey the moral law. If you think of liberty in those terms, you need to think again.
So our liberty in Christ, paradoxically, involves a positive kind of servitude as well. It's not an absolute freedom or moral autonomy.
Second, true Christian liberty is freedom from the yoke of the law.
Now this is the point at which many people get confused. Didn't I just say that Christian liberty doesn't erase the moral duties set forth in God's law?