—mysteries which purge out from soul and body even that sin which is hard to cleanse away, and which bring us back to that fairness of our first estate which God, the best of artificers, impressed upon us.
Therefore it is that you, the initiated people, are gathered together; and you bring also that people who have not made trial of them, leading, like good fathers, by careful guidance, the uninitiated to the perfect reception of the faith.
I for my part rejoice over both;—over you that are initiated, because you are enriched with a great gift: over you that are uninitiated, because you have a fair expectation of hope
—remission of what is to be accounted for, release from bondage, close relation to God, free boldness of speech, and in place of servile subjection equality with the angels.
For these things, and all that follow from them, the grace of Baptism secures and conveys to us.
[…] Christ, then, was born as it were a few days ago—He Whose generation was before all things, sensible and intellectual.
Today He is baptized by John that He might cleanse him who was defiled, that He might bring the Spirit from above, and exalt man to heaven, that he who had fallen might be raised up and he who had cast him down might be put to shame.
And marvel not if God showed so great earnestness in our cause: for it was with care on the part of him who did us wrong that the plot was laid against us; it is with forethought on the part of our Maker that we are saved.
And he, that evil charmer, framing his new device of sin against our race, drew along his serpent train, a disguise worthy of his own intent, entering in his impurity into what was like himself,—dwelling, earthly and mundane as he was in will, in that creeping thing.
But Christ, the repairer of his evil-doing, assumes manhood in its fulness, and saves man, and becomes the type and figure of us all, to sanctify the first-fruits of every action, and leave to His servants no doubt in their zeal for the tradition.
Baptism, then, is a purification from sins, a remission of trespasses, a cause of renovation and regeneration. […] And this gift it is not the water that bestows (for in that case it were a thing more exalted than all creation), but the command of God, and the visitation of the Spirit that comes sacramentally to set us free.
Gregory of Nyssa (c 335 – after 394): A Sermon for the Day of the Lights.