WHY DO WE DO THAT? - CATHOLIC LIFE EXPLAINED
This time of year, I attend a lot of weddings. Why do Catholic weddings need to take place in a church?
Technically, there is a clause in Church law that could allow for weddings to take place outside of a church, in a suitable space under special circumstances, but it requires the rare permission of the bishop. But the meaning of marriage goes very, very deep, and the Church has a vested interest in protecting that meaning. As Catholics, we don't see a wedding as an event that needs a pleasing backdrop.
Marriage is a sacrament, both an occasion of joyful promise and symbolic solemnity. It is a spiritual event. The loving bond of marriage symbolizes the mystical union between Christ and his Church. The man and woman profess lifelong vows of fidelity, and they receive supernatural grace from God to keep their promises. Receiving the sacrament of Marriage in a church has broader symbolic meaning for the couple as well. Marriage isn't simply two people in isolation from the world around them. Marriage is the joining of families and the beginning of a new, holy mission in the life of the couple. Weddings are sacred occasions, and it's fitting that they occur in sacred spaces.
"Our Lord prefers to wait Himself for the sinner for years
rather than keep us waiting for an instant." -- St. Maria Goretti