In the beginning of married life the partners are drawn to each other by lust as well as love; but with conscious and deliberate cooperation they can gradually lessen the element of lust and increase the element of love. Through this process of sublimation, lust ultimately gives way to  deep love. By the mutual sharing of joys and sorrows the partners march on from one spiritual triumph to another -from deep love to ever deeper love – till the possessive and jealous love of the initial period is entirely replaced by a self-giving and expansive love. In fact, through the intelligent handling of marriage they may traverse so much of the spiritual path that it needs only a touch by a Perfect Master to raise them into the sanctuary of Eternal Life.
-Discourses 7th Ed. p109