“We shall begin to understand the link between law and liberty if we go back to the very moment of the law giving at Mount Sinai. The LORD is speaking (Exodus 20:22) to those whom He has brought out of Egypt. They have been redeemed (Exodus 6:6) and the means of their redemption was the blood of the lamb (Exodus 12:13).
We see then that the LORD gives His law, not as a means to salvation but as a lifestyle for those who have already been saved. It is the way He wants His redeemed ones to live.But then he goes on to say that He is speaking to those for whom He has brought out of bondage (Exodus 20:2b) not to those whom He is bringing into bondage by imposing His law upon them, but those who are now for the first time enjoying liberty and to whom He gives His perfect law in order to safe guard the freedom He has secured for them.
True freedom is the opportunity and the ability to give expression to what we truly are. We are truly free when we live the life appropriate to those who are created in the image of God.
The Law of God safeguards that liberty for us, but it does even more for obedience brings life and power (Leviticus 18:5) (Deuteronomy 4:1a) (Acts 5:32).
The Law of God is the Law of liberty because it safeguards, expresses and enables the life of true freedom into which Christ has brought us.
This is the blessing of which James speaks the blessing of a full life, a true humanity; obedience is the key factor in our enjoyment of it.”
J.A. Motyer, The Message of James