Jesus said
"...from the beginning, the Creator made them male and female...and the two shall become one flesh." (Matt 19:4-5)
Therefore, the Sacrament of Matrimony is the matrimonial covenant, by which a man and a woman establish between themselves a partnership of the whole of life, which is by its nature ordered toward the good of the spouses and the procreation and education of offspring.
Marriage is love, the essence of which is a mutual self-giving without reservation, in the image of God's unconditional faithfulness to his creation and represents Christ's devotion to His Bride, the Church.