My logic is this:
There could be an all powerful god that was not compassionate. If so, I despise it.
There could not under any circumstances be an all powerful god is compassionate. Evidence rules this out.
Any other "super being" is not really a god, it's just something we could probably out Evolve.
I haven't seen any evidence for any god anyway, so I live my life assuming there isn't one.
I've always been your situation! I've always asked God, why? why if you are real, do you allow this? But unlike you, I still take his name and try to help where I can. My heart doesn't believe God is evil, I don't know why!
There are verses in the GGS that made my grandad atheist, but I don't know why I still cling to God. I'll try to find those verses. Would you mind having a look at them and understanding what baba nanak was trying to say? I don't understand them.