Catholic Candle note: God put us on earth to begin (and then to advance in) the spiritual life. But how do we do this? As always, the Catholic Church has the answer!
In Sacred Scripture and in the teachings of the Doctors of the Church, the Church gives us many helps and explanations. One tremendous guide to understanding how to advance in the spiritual life, is the comparison of how our spiritual life is like a happy and harmonious, good Catholic marriage.
Charity (and the whole spiritual life) are inherently Divine Friendship. More specifically, the spiritual life should be a spiritual marriage between Christ and each of our souls. Because spouses should be the very best of friends, marriage is the perfect figure for this union we should have with Christ.
The Canticle of Canticles is full of this imagery of marriage and romantic interchange of lovers, as a way to teach us about the spiritual relationship we should have with Christ. This spiritual marriage is a soul’s complete surrender to Christ in all things, a total generosity which is prefigured by a happy and harmonious, good Catholic marriage.
Not only should our souls be spouses of Christ, but they should be as a bride, not as the bridegroom, in this spiritual marriage. Christ calls Himself the Bridegroom, not the bride. St. Matthew’s Gospel, 9:15.
Concerning this spiritual marriage which our souls should have with Christ, the great Mystical Doctor, St. John of the Cross, continually calls the soul Christ’s bride and “a maiden”.
Fittingly, the usual word for “soul” (in Latin) is “anima”, which is in the feminine declension, showing the disposition the soul should have towards Christ. For:
Ø Just as a wife should be passive and receptive to her husband and be led by him (rather than leading him), likewise the soul should be passive and receptive to her Spouse, Christ, and be led by Him.
Ø Just as a bride joins her husband’s life, leaving behind her past life (fittingly signifying this by taking his last name) likewise the soul joins Christ’s Life, and leaves behind her past life.
Let us strive all we can that our souls are good brides to their Spouse, Our Lord Jesus Christ! Let them be passive and receptive to Christ! Let them be led wherever Christ leads! Let them leave behind them their past lives and completely join His life!
 Here is how St. Thomas Aquinas, greatest Doctor of the Church, explains this truth:
It is written (John 15:15): “I will not now call you servants . . . but My friends.” Now this was said to them by reason of nothing else than charity. Therefore, charity is friendship. …
According to the Philosopher (Ethic. viii, 2,3) not every love has the character of friendship, but that love which is together with benevolence, when, to wit, we love someone so as to wish good to him. If, however, we do not wish good to what we love, but wish its good for ourselves, (thus we are said to love wine, or a horse, or the like), it is love not of friendship, but of a kind of concupiscence. For it would be absurd to speak of having friendship for wine or for a horse.
Yet neither does well-wishing suffice for friendship, for a certain mutual love is requisite, since friendship is between friend and friend: and this well-wishing is founded on some kind of communication.
Accordingly, since there is a communication between man and God, inasmuch as He communicates His happiness to us, some kind of friendship must needs be based on this same communication, of which it is written (1 Corinthians 1:9): “God is faithful: by Whom you are called unto the fellowship of His Son." The love which is based on this communication, is charity: wherefore it is evident that charity is the friendship of man for God.
Summa, IIa IIae, Q.23, a.1, sed contra and respondeo.
 See, e.g., Spiritual Canticle, St. John of the Cross, Stanza XVIII.
Comparing the spiritual life to Christ’s relationship with souls – even men’s souls – does not conflict with men’s nature. Although men should be manly and not womanly, there is no contradiction with a man’s soul being as a bride of Christ in a spiritual marriage with Him, and yet still being a manly man of his wife and being the head of his home and of his wife. St. Paul shows this compatibility when he teaches that “the husband is the head of the wife, as Christ is the head of the Church”. Ephesians, 5:23.