Here's the good doctor (Martyn Lloyd-Jones) in The Assurance of Our Salvation on the law and Christ:
What he [Christ] has done for us is that he has satisfied the law and all its demands. It is amazing to me how people can look at and preach about Christ, his life and death and never mention the law. But unless the law of God is satisfied, there is no salvation. The law is opposed to us; it stands there and demands a perfect, absolute obedience and it threatens us with death if we fail in any one respect. If Christ has not fulfilled the law, we are yet in our sins, we are undone, we are damned and we are lost, but he has finished the work, the books have been cleared, the law has been satisfied, there is therefore no condemnation to them that are in Christ Jesus. Do you know that? Are you rejoicing in it? Are you ready to take your stand with Toplady and say:
The terrors of law and of God
With me can have nothing to do,
My Saviour’s obedience and blood
Hide all my transgressions from view.