God is Perfect because of everything he created. The planets, the animals, nature, weather etc. God is perfect because He doesn't eat nor sleep, He is Ever-Living, Powerful. Everything came into existence because of God. I can go on further but I'll stop here.
God isn't just All-Loving, God is also The Just, The Punisher, etc. many people want to believe God is The All Merciful, so they can do whatever they want, commit as many sins as they want but then believe that since God is so Merciful and Loving, that they will enter Heaven.
It's human nature to want to be right, or feel like what they're doing is right. That's why athiests challenge thiests and vice versa. They want to prove the others wrong.