If we believe in God, we must also do what God asks. Our Lord Jesus Christ said "It is not those who cry out ‘Lord, Lord’ who will enter the kingdom of God, but those who do the will of My Father in heaven".
Jesus also said "You will live in My love if you keep My commandments, just as I have kept My Father’s commandments, and live in His love". Therefore, we must obey God’s commandments and keep His law.