> The main problem is not the idea of God (imho god = love)

Well there goes your problem, you're countering something that these religions don't claim in the first place: None of the Abrahamic religions (Christianity, Judaism, Islam, etc.) claim that God is pure love, butterflies and spreads happiness on earth.

Their scriptures explicitly talk about how life on earth is (also) filled with pain, disease and man-created problems.

I'm not sure why this criticism ("What kind of god gives kids cancer") on religion is so common in Western countries... it's a giant strawman that a simple question to a believer of such religion would dispell.