If God knows what people will choose, why did God regret creating human beings on the earth? Did God know that people would be bad but He didn't know how bad they would be? -- Jennie. K.

God regretted in terms of emotion. However we think about this matter, we need to take into account Gen 6:6: And the Lord was sorry that he had made humankind on the earth, and it grieved him to his heart. He isn't just a colossal cosmic computer, but has feeling and will and understanding. 

Yet his regret is different than human regret. We regret it when we do wrong, as well as regretting it when we’ve done nothing wrong but the situation turns out bad anyway. For God, of course, it’s the second type of regret.

This discussion is closely tied to the issue of whether the Lord truly changes his mind (as opposed to postponing his actions). Some older Bible versions occasionally have God “repenting” when things go wrong. Of course “repent” implies sin. A far better translation would be “relent.”

Anyway, I hope this is helpful. Further material at the website you might appreciate, all somewhat related to God’s creation of man on earth: