Why does God treat sin like cooties?

God deals with evil in a very childish manner. Why do people believe we are more sinful now than everyone was in biblical times. They seem to forget about the human sacrifices, genocides, , and torture that happened back then, but somehow gay marriage, masturbation, and marijuana is worst. These are apparently, the reasons why God won't show is face, according to religious believers, however he had no problem doing it 2000 years ago. Please explain this logic. Is it really ok to ume God is returning, been here at all, or even exists?