10 Come then, be begotten again, O man, into the adoption of God. And how? Says one. If you practise adultery no more, and commit not murder, and serve not idols; if you are not overmastered by pleasure; if you do not suffer the feeling of pride to rule you; if you clean off the filthiness of impurity, and put off the burden of sin; if you cast off the armour of the devil, and put on the breastplate of faith, even as Isaiah says, “Wash, and seek judgment, relieve the oppressed, judge the fatherless, and plead for the widow.
And come and let us reason together, says the Lord. Though your sins be as scarlet, I shall make them white as snow; and though they be like crimson, I shall make them white as wool. And if you be willing, and hear my voice, you shall eat the good of the land.” Do you see, beloved, how the prophet spoke beforetime of the purifying power of baptism? For he who comes down in faith to the layer of regeneration, and renounces the devil, and joins himself to Christ; who denies the enemy, and makes the confession that Christ is God; who puts off the bondage, and puts on the adoption,— he comes up from the baptism brilliant as the sun, flashing forth the beams of righteousness, and, which is indeed the chief thing, he returns a son of God and joint-heir with Christ.
To Him be the glory and the power, together with His most holy, and good, and quickening Spirit, now and ever, and to all the ages of the ages. Amen.
Source: Discourse on the Holy Theophany (New Advent)