The free to marry has long been recognised as one of the vital personal rights essential to the orderly pursuit of happiness by free men. The law banning interracial marriages violated both the equal protection and due process clauses of the 14th amendment. But the constitution to prohibit gay marriage is the same situation with the law banning interracial marriage. California granted marriage licences to some gay couples. why has the gay marriage in the secular world? It seems that the gay marriage violate the nature of human being development process. The current world is becoming more and more strange. Maybe it is difficult to find a ideal soulmate in opposite sex.