Did God make a U-turn from sin?
And God saw their works, that they turned from their evil way; and God repented of the evil, that he had said that he would do unto them; and he did it not.
Jonah 3:10 KJV
No, God repented - he changed his mind.
However we do see what making a u-turn is in the verse above
And God saw their works, that they u-turned from their evil way. Jonah 3:10
Nineveh's repentance is here, a few verses earlier:
So the people of Nineveh believed God, and proclaimed a fast, and put on sackcloth, from the greatest of them even to the least of them.
Jonah 3:5 KJV
First you repent (change your mind from unbelief) and after salvation you change your ways especially if you want fellowship with God, otherwise life will be far from fun.
Jesus equates repentance with faith:
For John came unto you in the way of righteousness, and ye believed him not; but the publicans and the harlots believed him: and ye, when ye had seen it , repented not afterward, that ye might believe him.
Matthew 21:32 KJV
In other words Jesus told the pharisees that even after all they witnessed they still didn't repent (change their mind) and believe.
Granville Sharp rule shows faith and repentance the same:
If God's people want to be blessed and healed, Christians must turn from their sins.
if my people, which are called by my name, shall humble themselves, and pray, and seek my face, and turn from their wicked ways; then will I hear from heaven, and will forgive their sin, and will heal their land.
Did God make a U-turn from sin?
2 Chronicles 7:14 KJV