20 And do not think, dearest brother, that either the courage of the brethren will be lessened, or that martyrdoms will fail for this cause, that repentance is relaxed to the lapsed, and that the hope of peace is offered to the penitent. The strength of the truly believing remains unshaken; and with those who fear and love God with their whole heart, their integrity continues steady and strong. For to adulterers even a time of repentance is granted by us, and peace is given.
Yet virginity is not therefore deficient in the Church, nor does the glorious design of continence languish through the sins of others. The Church, crowned with so many virgins, flourishes; and chastity and modesty preserve the tenor of their glory. Nor is the vigour of continence broken down because repentance and pardon are facilitated to the adulterer. It is one thing to stand for pardon, another thing to attain to glory: it is one thing, when cast into prison, not to go out thence until one has paid the uttermost farthing; another thing at once to receive the wages of faith and courage.
It is one thing, tortured by long suffering for sins, to be cleansed and long purged by fire; another to have purged all sins by suffering. It is one thing, in fine, to be in suspense till the sentence of God at the day of judgment; another to be at once crowned by the Lord.
Source: The Epistles of Cyprian (New Advent)