Bear in mind I don't insist that a deity be benevolent. I'm a big fan of Crom and Cthulhu.
I'm speaking of predestination as in "God has a plan."
If God has a plan, then I can't have free will.
If I can make a choice that thwarts God's plan, he can't be much of a deity.
There are folks, and I'm not saying you are one of them, that insist that God knows what you're going to do and therefore both these things can exist simultaneously.
I think you can have free will and predestination at the same time.
Think of a rushing river and you are a droplet. You can bounce here, you can bounce there, but the river, it flows on its path. Nothing you do can alter it.