To speak of love is to dare to speak of God, for, according to St John the Theologian, ‘God is love, and he who dwells in love dwells in God’ [1 Jn 4.16]. And the astonishing thing is that this chief of all the virtues is a natural virtue. Thus, in the Law, it is given pride of place: ‘You shall love the Lord your God with all your heart, and with all your soul, and with all your might’ [Deut 6.5]. When I heard the words ‘with all your soul’ I was astounded, and no longer needed to hear the rest. For ‘with all your soul’ means with the intelligent, incensive and desiring powers of the soul, because it is of those three powers that the soul is composed. Thus the intellect should think at all times about divine matters, while desire should long constantly and entirely, as the Law says, for God alone and never for anything else; and the incensive power should actively oppose only what obstructs this longing, and nothing else. St John, consequently, was right in saying that God is love. If God sees that, as He commanded, these three powers of the soul aspire to Him alone, then, since He is good, He will necessarily not only love that soul, but through the inspiration of the Spirit will dwell and move within it [cf 2Cor 6.16; Lev 26.12]; and the body, though reluctant and unwilling–for it lacks intelligence–will end by submitting to the intelligence, while the flesh will no longer rise in protest against the Spirit, as St Paul puts it [cf Gal 5.17].
Just as the sun and moon, at the command of God, travel through the heavens in order to light the world, even though they are soul-less, so the body, at the behest of the soul, will perform works of light. As the sun journeys each day from east to west, thus making one day, while when it disappears night comes, so each virture that a man practices illumines the soul, and when it disappears passion and darkness come until he again acquires that virtue, and light in this way returns to him. As the sun rises in the furthest east and slowly shifts its rays until it reaches the other extreme, thus forming time, so a man slowly grows from the moment he first begins to practice the virtues until he attains the state of dispassion. And just as the moon waxes and wanes every month, so with respect to each particular virtue a man waxes and wanes daily, until this virtue becomes established in him. At times, in accordance with God’s will, he is afflicted, at times he rejoices and gives thanks to God, unworthy as he is to acquire the virtues; and sometimes he is illumined, sometimes filled with darkness, until his course is finished.
All this happens to him by God’s providence: some things are sent to keep him from self-elation, and others to keep him from despair. Just as in this present age the sun creates the solstices and the moon waxes and wanes, whereas in the age to come there will always be light for the righteous and darkness for those who, like me, alas, are sinners, so, before the attainment of perfect love and of vision in God, the soul in the present world has its solstices, and the intellect experiences darkness as well as virtue and spiritual knowledge, and this continues until, through the acquisition of that perfect love to which all our effort is directed, we are found worthy of performing the works that pertain to the world to be. For it is for love’s sake that he who is in a state of obedience obeys what is commanded; and it is for love’s sake that he who is rich and free sheds his possessions and becomes a servant, surrendering both what he has and himself to whoever wishes to possess them. He who fasts likewise does so for love’s sake, so that others may eat what he would otherwise have eaten. In short, every work rightly done is done out of love for God or for one’s neighbor. The things we have spoken of, and others like them, are done out of love for one’s neighbor, while vigils, psalmody and the like are done out of love for God. To Him be glory, honour and dominion through all the ages. Amen.
St Peter of Damaskos (eleventh or twelfth century), Discourse XV
Philokalia, Volume III