Husband and wife, by the covenant of marriage, are no longer two, but one flesh. By their intimate union of persons and of actions they give mutual help and service to each other, experience the meaning of their unity, and gain an ever deeper understanding of it day by day. This intimate union in the mutual self-giving of two persons, as well as the good of the children, demands full fidelity from both, and an indissoluble unity between them. Christ the Lord has abundantly blessed this richly complex love which springs from the divine source of love and is founded on the model of his union with the Church.