but anyways an omnipotent being, which so many claim god to be, would know if its creations would one day turn bad,
You mean omni
scient. But yes He would know this before creating them.
and were this being also to be completely benevolent, it would do something to prevent it, as a truly good being doesn't want the suffering of evil to exist, because when evil exists it doesn't just hurt the person who decides to be evil, but it hurts everyone they come into contact with as well. It might make sense to allow people to be evil should it only hurt them, but what of all the good people who suffer and die as a result, what of the free wills of those people which are violated by the evil people? And if you consider being apathetic towards evil around you to be a form of evil, then god would be the worst offender in the history of all of existence, because unlike people, god could intervene anytime it wanted without risk or effort on its part.
you argue that if God is omnibenevolent then He would not create free creatures who He knew beforehand would eventually decide to do evil things.
Now, there are two trains of thought pertinent here. First is the intellectual problem of evil and it concerns how to give a rational explanation of how God and evil can co-exist. The emotional problem of evil concerns how to dissolve peoples emotional dislike of a God who would permit suffering.
I think your objection is more along the lines of the latter. But if it is not, I will address the former to cover all bases.
Now lets look first at the intellectual problem of evil. There are two versions of this problem.
First, the logical problem of evil.
Second, the probabilistic problem of evil.
According to the logical problem of evil, it is logically impossible for God and evil to co-exist. If God exists, then evil cannot exist. If evil exists, then God cannot exist. Since evil exists, it follows that God does not exist.
The problem with this argument is that theres no reason to think that God and evil are logically incompatible. Theres no explicit contradiction between them. Maybe you object and say that theres some implicit contradiction between God and evil.
Ok, well, what premises do you use to bring out this implicit contradiction? No philosopher has ever been able to identify such premises. Therefore, the logical problem of evil fails to prove any inconsistency between God and evil.
Actually it is easy to prove that God and evil are logically consistent. You are arguing that the problem of evil presupposes that God cannot have morally sufficient reasons for permitting the evil in the world. But this assumption is not
necessarily true. So long as it is even possible that God has morally sufficient reasons for permitting evil, it follows that God and evil are logically consistent. And, certainly, this does seem at least logically possible. In virtue of this it is widely agreed among contemporary philosophers that the logical problem of evil has been dissolved. The co-existence of God and evil is logically possible.
This is why the logical problem of evil is not defended by any prominent non-theists.
Now, if you have all that down, we can move to the probabilistic problem of evil.