This is all speculation on my part ... but you get it anyway ... I pulled this post that I wrote from a forum that I visit

OK, I went to a brief talk on Theology of the Body and it got me to thinking ... in Ephesians 5 Paul links the relationship between Christ and the Church to that of a husband and wife. So I got to thinking a little more ... We have our 4 marks of the Church

One
Holy
Catholic
Apostolic

Can we draw similar parallels to marriage and family? I need some good examples here ...

One - yeah this is obvious ... "two become one flesh"
Holy - well God certainly intends this of marriage. Divorce, adultery etc. are certainly not supposed to be part of marriage.
Catholic - well marriage has been around for as long as we have history ... and it permeates most, if not all, cultures
Apostolic - results in generations or "passing on" -- include family traditions etc ...

I think there is a point that can be made about the concept of the "invisible church".

Marriage, quite simply, is visible. It mirrors those marks because that is the REALITY of the Church. For marriage to be analogous to the invisible Church God would have to create families or groups of generations (denominations) from nothing, because there is no generational link (apostolic) ... Honestly I think the Church was set up the way it was because God wanted it to be a sign to us regarding marriage and also allowing our marriages to be a sign to help us identify the Church.

In other words, the visiblity of the Catholic Church better represents the reality of marriage and vice versa. Ok enough of my theorizing ... carry on