God, the Christian God, is omnipotent, omniscient, and omnipresent. He is infallible. He is perfectly good. He is in total and complete charge of everything to a level far deeper than every single atom.
So where does that put free will?
I'm informed that this is good Baptist orthodoxy, even though I got it from C.S. Lewis. God is in Eternity, and outside, at least in part, of Time/Space. To Him, yesterday, today, and tommorrow are the same thing. He can flip to the back of the book, read the last page, and then shift to the middle of the book, and read a page there. But the reader of an ordinary book no more controls the actions of the characters than does God, even though this hypothetical reader would also know the future equally with the present.
Then why does God allow Evil?
Human freedom is close to the most valuable thing in the cosmos with exceptions like the Blood of Christ. Freedom is more valuable by a longshot than human happiness. In order to have Freedom, you have to have a choice. In order for it to be a meaningful choice, you have to have consequences.
Take away consequences and you take away freedom.
Then why do bad things happen to people?
1)They do something bad. You drink to excess, and you have a hangover.
2)Someone else did something bad. The other guy drank too much, got in his car, and ran you over. Thats a consequence of his ill choice.
3)Someone else did something bad way long ago. You grow up poor because your great-grandfather who was on his way to the patent office with a brilliant invention was run over by a guy driving drunk in his carriage. Your grandfather was overwrought at the loss, and raised his kids poorly, and so now you have a line of children raised in neglect and poverty when if one guy hadn't taken the stagecoach out for a drunken spin might have been a family line of wealth, love, and talent to help the world.
4)Its a finite world. You make the best choice possible on the available information, and its the wrong choice. Only God is infinite, has perfect information, and no character limits. So in my view, even angels can mess up, even though they cannot sin.
5)Someone chooses to do evil.