How is gay marriage an abomination to churches (Please read carefully)?

because Any child knows that God created Adam and Eve not Adam and Steve! blah blah blah but there is priests molesting children all over the World? which also should be a sin because they are corrupting God's children and they are suppose to be dedicating their lives to churches. and there is nothing about that in the bible but then why is gay marriage a sin? i support gay marriage!