Ehhhhhhh. You're conflating this existence with all of eternity. Those are very different things.
Consider God as a parent. I used the example in an earlier response but my friend took her child to be vaccinated. For a baby, that's a very unpleasant day. In a week, she won't remember it.
Similarly, an all powerful, good God can be okay with someone suffering for a momentary blip because the end result is an eternity of paradise. (What is a lifetime of suffering against infinite years of happiness?)
"But wait!" you cry, "surely an all powerful God can skip the ANY suffering bit, right? He's just choosing not to because he's a prick!" Which misses the possibility of self imposed constraints on power. If I build a system and choose to work within that system, that's still me being all powerful. And if, as an all knowing being, I know that a half moment of unpleasantness means an eternity of bliss (so I can reward free will, instead of just creating a bunch of automatons), that's a tradeoff a good and all powerful God may make.