The main problem with this entire question is that no one really has the right to decide what is good or evil. So God is all good. What exactly is good? Either humans or some kind of sentient beings decide, in which case there are a few millions of definitions, none totally consistant with another, to pick from. If God decides, the expression can lose its original meaning as we know it, and simply mean 'what God is/does'.
The people who believe in the Christian God usually believe that there is one true definition of 'good', that God made it and that it includes letting evil exist, or even creating it. I don't see what's so strange about that.
The people who believe in the Christian God usually believe that there is one true definition of 'good', that God made it and that it includes letting evil exist, or even creating it. I don't see what's so strange about that.