Do I have to do what the bible says?

From the mouth of Jesus, he asks a question, how could you say you follow me and not do what I tell you to do?

Luke 6:46-47
46 “Why do you call me ‘Lord, Lord,’ and not do what I tell you? 47 Everyone who comes to me and hears my words and does them, I will show you what he is like:

Deuteronomy 6:6 indicates that the laws of God should be written on the heart and actions of each believer.
5 You shall love the LORD your God with all your heart and with all your soul and with all your might. 6 And these words that I command you today shall be on your heart. 7 You shall teach them diligently to your children, and shall talk of them when you sit in your house, and when you walk by the way, and when you lie down, and when you rise. 8 You shall bind them as a sign on your hand, and they shall be as frontlets between your eyes. 9 You shall write them on the doorposts of your house and on your gates.

From the very beginning of the world it is God’s spoken word which has caused all things to be. See Genesis 1:3ff
3 And God said, “Let there be light,” and there was light.

Exodus 20:1ff indicates that God’s laws come from his very mouth
And God spoke all these words, saying, 2 “I am the LORD your God, who brought you out of the land of Egypt, out of the house of slavery. 3 “You shall have no other gods before me.