If god doesn't like sins, why does he/she let it happen?

if people didn't commit sins, there would be no wrong doings in the world. therefore there would be no hate, war, poverty, terrorism, genocides, and all other bad things. From these experiences, we learn to reach out to those who are suffering, and help them when they need it most, thus making us better people, because of other peoples sins and the affect we have on those who have been hurt by them. And in a way, it's also a test of ones faith (if you are religious). I'm an atheist and that's how I look at it.