Catechism of the Catholic Church

This is what the Apostle Paul makes clear when he says: "Husbands, love your wives, as Christ loved the church and gave himself up for her, that he might sanctify her," adding at once: "For this reason a man shall leave his father and mother and be joined to his wife, and the two shall become one. This is a great mystery, and I mean in reference to Christ and the Church."