Q.49: What does the preface to the Ten Commandments teach us?
A. The preface to the Ten Commandments teaches us that because God is the Lord, and our God and Redeemer, therefore we are bound to keep all His commandments.
But as He who called you is holy, you also be holy in all your conduct, because it is written, “Be holy, for I am holy.” And if you call on the Father, who without partiality judges according to each one’s work, conduct yourselves throughout the time of your stay here in fear; knowing that you were not redeemed with corruptible things, like silver or gold, from your aimless conduct received by tradition from your fathers, but with the precious blood of Christ, as of a lamb without blemish and without spot. 1 Peter 1:15-19