Does God Limit His Own Power

Since never reading anything by CS Lewis before, the Problem of Pain has been how can you say, one of the most amazing book i think i have ever read, though it has made me think a lot, the early chapter, made me begin to wonder, Lewis talks about how God can do all things that are possible, but many people believe that God is all powerful, since never been brought to the idea that can can't do all things that made me wonder, does he limit his own powers. has he made things so that he can only act in certain ways, so that he does not overdo it or something. Did God by making us a free-willed person purposefully disallow himself from being able to rid all evil, i am not saying that he cant but to take away all evil and pain, but if he did he would be breaking his own laws, and rules the ones that have been there since the fall of man. So is God all powerful, and has just limited his own power by his own laws, or is he just able to do the things that are possible to cognitively create.