Inbreeding

No religion accept inbreeding ( sexual relationship with sibling) . If you look at the abrahamic religion history, Adam's children was brother and sisters and they all mated with one and another and practiced inbreeding. Since it was God first human couple, he obviously encouraged inbreeding. If he found our inbreeding was dangerous then obviously he is not that smart. Why didn't he created 2 couple??  And one more thing why did he created all the genetic problem associated with inbreeding ?