The Catholic church closely safeguards the sanctity of marriage because it is a reflection of Christ's union with his bride, the church, Pope Francis said.
Jesus often uses the imagery of a bridegroom to help people see the nature of his relationship with the church, the pope said Friday during his morning Mass in his residence of the Domus Sanctae Marthae.
"I think this is exactly the most profound reason why the church safeguards the sacrament of Marriage so much and calls it the great sacrament, because it is precisely the image of the union of Christ with the church."
Another parallel between a nuptial banquet and the faith is that Christians are called to be joyful guests gathered together, the pope said.
While there will be great trials and moments of pain in life, "a Christian is fundamentally joyful," he said, because everyone is invited to a great celebration: "the nuptials of Jesus with the church."
Jesus is also "the head of the body of the church," and in him all things are reconciled, the pope said, referring to the day's reading from the Letter of St. Paul to the Colossians, "In him were created all things."
Jesus is to be recognized as "the one and only," who "is always faithful and asks us to be faithful."
Jesus asks people to experience the joy of celebration, "the joy of being Christian, and he also asks us for totality, that it's all him."
"If we have something that isn't about him, repent, ask forgiveness and keep going," the pope said.
People cannot serve two masters, he said; a person can either serve God or the world.