One religious answer to the problem of evil is the idea that sin is necessary in order to allow people to exercise their free will. Apparently, if God had created a perfect world, we would all be robots with no free will, and that would be a terrible thing.
But wait a minute. Heaven is supposed to be a perfect world. God, the angels, and all the saints are supposed to live in heaven forever. If free will requires sin in order to be free will, then the sinlessness of heaven means God, the angels, and all the saints are going to spend eternity not having any free will.
That means that for us to have free will right now is a complete waste. The only thing it contributes is to send most of God’s “beloved” children to the eternal torments of Hell. Only the elect few will make it to the realm where their free will no longer exists, and the Bible says that the saved were foreordained before the foundation of the world, so in a sense their “free” will was illusory even while they had it. That’s not much of a justification for sin, is it?
If we compare time and eternity, where time is finite and eternity is infinite, then the relative importance of anything that happens in time is insignificant. That means that temporary free will has, at best, an insignificant benefit for those who experience it. The religious claim is that it has a tremendous benefit in that it determines whether you spend eternity in heaven or in hell, but this overlooks the fact that God could have sent all His children straight to eternity in heaven simply by skipping the part where He jeopardizes their salvation by exposing them to a fleeting, useless, and pointless free will.
If we say that free will requires sin, therefore, we have a dilemma. Once the saved get to heaven, there cannot be any further opportunity for them to have free will, since there is no sin. That means heaven cannot be perfect unless there is no eternal value in free will, because otherwise the lack of free will would be a deficiency that would keep heaven from being perfect. The perfection of heaven therefore requires either that free will has no value or else that people are lying when they say free will requires sin.
If free will has no value, then God gains nothing by putting us through it, and indeed loses most of that which He allegedly loves, when they sin and go to Hell. But if free will can exist without sin, then the whole argument collapses, because free will was supposed to explain why God’s perfect creation ended up full of sin and evil. If we could have been just as free by choosing between, say, chocolate and vanilla instead of between good and evil, then God’s decision to allow sin to enter the world really only serves to degrade a situation that could and should have been much better. That means God is either weak, or foolish, or evil, or all of the above.
The problem of evil is just one aspect of a much larger problem, which is that reality looks nothing at all like the conditions that would exist if there were a God as mighty and wise and loving as the character who shows up in Gospel stories. Religious people try to account for the more obvious discrepancies by means of various rationalizations, but these rationalizations themselves have internal contradictions and inconsistencies that are just as bad as the discrepancies they’re trying to explain away. The only reasonable conclusion is that the Gospel is a myth drawn from the wishful thinking of superstitious people.