I Will Walk At Liberty: For I Seek Thy Precepts

Today the Law of God is held up as an enemy of liberty. The psalmist says "I Will Walk At Liberty: For I Seek Thy Precepts".
What place, if any, has the Law of God in the life of a believer? The old writers would have us know that, Sin is the transgression of the Law, the death of Christ is the satisfaction of the Law, justification is the verdict of the Law and sanctification is believers fulfillment of the Law.
If the Christian is no longer under the law, but under grace, does that mean the Christian is lawless? Does it mean that the Law of Christ is at odds with the law of Moses?
Was Ralph Erskine right when he wrote
"When by the law to grace I'm schooled;
Grace by the Law will have me rul'd
Hence, if I don't the law obey
I cannot keep the gospel way?"
We will make an attempt to consider some of these things