Marriage is based on biology/ The tradition is simply that marriage is an institution that has developed to provide care for human progeny, which takes a long while to mature, and which must not only be nurtured but educated. Homosexuality makes sex,or rather the pleasure that goes with it, which are intended to produce children, an end in itself. In demanding the rights attendent to marriage, the homosexual couple take away the resources of society that ought to go toward the rearing of children. But there is another evil that goes with this: the gays demand that the schools inculcate their sexual morality in children, thereby driving a wedge between them and those parents who reject this morality.
It has also developed for one spouse to provide care for the other. In addition, lesbians can have children; nothing prevents one or both of them getting knocked up and raising those kids together.
homosexual couple take away the resources of society that ought to go toward the rearing of children.
What resources are those?
the gays demand that the schools inculcate their sexual morality in children
I haven't seen this personally, but that I will fight against.