Then it isn’t marriage in the true sense if they are not married in the eyes of God.
And they can determine property rights, child custody already without the state sanction of marriage and divorce would become a non-issue.
That’s nice, you have a personal opinion and a religion, I’m sure we have a lot of different opinions in a free nation, FLDS has their opinions, the Muslims have theirs, the gay churches have theirs, the atheists who want to marry, and have the right to, have theirs.