Tertullian, On Exhortation to Chastity 1

I do not doubt, brother, that after your wife went ahead of you in peace you have turned your mind to composing yourself and are now weighing what it means to stay single — and you certainly need counsel. True, everyone ought to hash this out with his own faith and test its strength; but because the flesh's necessity keeps prodding the thought, and that necessity almost always resists the very conscience of faith, you need faith's counsel from outside, like an advocate against the flesh's demands. That necessity is easily overcome if you weigh God's will instead of indulgence. No one earns anything by claiming indulgence; you earn by obeying the will. And God's will is our sanctification. He wants us to become his image and likeness so that we may be holy as he is holy. That good — sanctification, I mean — he parcels out into several forms so that we might be caught in one of them. The first form is virginity from birth. The second virginity comes from the second birth, that is, from baptism: it either keeps itself pure within marriage by mutual agreement, or it perseveres in widowhood by choice. The third step left is monogamy: after one marriage ends, you renounce sex altogether. The first virginity is happiness — never knowing at all the thing you will later long to be free of. The second is virtue — despising the power you know all too well. The remaining form, marrying again after death has dissolved a marriage, wins praise not only for virtue but also for modesty. For modesty means not craving what has been taken away, and taken away by the Lord God, without whose will not a leaf falls from a tree nor a sparrow drops to the ground for a single coin.