Luke 3:21

(De unit. Eccles.) the dove is a harmless and pleasant creature, with no bitterness of gall, no fierceness of bite, no violence of rending talons; they love the abodes of men, consort within one home, when they have young nurturing them together, when they fly abroad, hanging side by side upon the wing, leading their life in mutual intercourse, giving with their bills a sign of their peaceful harmony, and fulfilling a law of unanimity in every way.

(De Dec. Nic. Syn.) The holy Scriptures by the name of Son set forth two meanings; one similar to that spoken of in the Gospel, He gave to them power that they should become the sons of God; another according to which Isaac is the son of Abraham. Christ is not then simply called a Son of God, but the article is prefixed, that we should understand that He alone is really and by nature the Son; and hence He is said to be the Only begotten. For if according to the madness of Arius He is called Son, as they are called who obtain the name through grace, He will seem in no way to differ from us. It remains therefore that in another respect we must confess Christ to be the Son of God, even as Isaac is acknowledged to be the son of Abraham. For that which is naturally begotten of another, and takes not its origin from any thing besides nature, accounts a son. But it is said, Was then the birth of the Son with suffering as of a man? By no means. God since He cannot be divided is without suffering the Father of the Son. Hence He is called the Word of the Father, because neither is the word of man even produced with suffering, and since God is by nature one, He is the Father of one only Son, and therefore it is added, Beloved. For when a man has only one son, he loves him very much, but if he becomes father of many, his affection is divided by being distributed. But as the prophet had before announced the promise of God, saying, I will send Christ my son, that promise being now as it were accomplished at Jordan, He rightly adds, In thee I am well pleased.

(in Orat. 39.) Christ comes also to baptism perhaps to sanctify baptism, but doubtless to bury the old Adam in water.

In a matter which has been related by others, Luke has rightly given us only a summary, and has left more to be understood than expressed in the fact, that our Lord was baptized by John. As it is said, Now when all were baptized, it came to pass. Our Lord was baptized not that He might be cleansed by the waters but to cleanse them, that being purified by the flesh of Christ who knew no sin, they might possess the power of baptism. But the cause of our Lord's baptism He Himself declares when He says, Thus it becomes us to fulfil all righteousness. But what is righteousness, except that what you would have another do to you, you should first begin yourself, and so by your example encourage others? Let none then avoid the laver of grace, since Christ avoided not the laver of repentance. Now the Spirit rightly showed Himself in the form of a dove, for He is not seen in His divine substance. Let us consider the mystery why like a dove? Because the grace of baptism requires innocence, that we should be innocent as doves. The grace of baptism requires peace, which under the emblem of an olive branch the dove once brought to that ark which alone escaped the deluge. We have seen the Spirit, but in a bodily shape, and the Father whom we cannot see we may hear. He is invisible because He is the Father, the Son also is invisible in His divinity, but He wished to manifest Himself in the body. And because the Father did not take the body, He wished therefore to prove to us that He was present in the Son, by saying, Thou art my Son.

Now there was a Jewish baptism which removed the pollutions of the flesh, not the guilt of the conscience; but our baptism parts us from sin, washes the soul, and gives us largely the outpouring of the Spirit. But John's baptism was more excellent than the Jewish; for it did not bring men to the observance of bodily purifications, but taught them to turn from sin to virtue. But it was inferior to our baptism, in that it conveyed not the Holy Spirit, nor showed forth the remission which is by grace, for there was a certain end as it were of each baptism. But neither by the Jewish nor our own baptism was Christ baptized, for He needed not the pardon of sins, nor was that flesh destitute of the Holy Spirit which from the very beginning was conceived by the Holy Spirit; He was baptized by the baptism of John, that from the very nature of the baptism, you might know that He was not baptized because He needed the gift of the Spirit. But he says, being baptized and praying, that you might consider how fitting to one who has received baptism is constant prayer. But he says, The heavens opened, as if till then they had been shut. But now the higher and the lower sheep-fold being brought into one, and there being one Shepherd of the sheep, the heavens opened, and man was incorporated a fellow citizen with the Angels. The Holy Spirit descended also upon Christ as upon the Founder of our race, that He might be in Christ first of all who received Him not for Himself, but rather for us. Hence it follows: And the Holy Spirit descended. Let not any one imagine that He received Him because He had Him not. For He as God sent Him from above, and as man received Him below. Therefore from Him the Spirit fled down to Him, i. e. from His deity to His humanity. That baptism savoured partly of antiquity, partly of novelty. For that He should receive baptism from a Prophet showed antiquity, but the Spirit's descent denoted something new. Or to show the meekness of the Lord, the Spirit now appears in the form of a dove, but at Pentecost like fire, to signify punishment. For when He was about to pardon offences, gentleness was necessary; but having obtained grace, there remaineth for us the time of trial and judgment. Christ indeed had already manifested Himself at His birth by many oracles, but because men would not consult them, He who had in the mean time remained secret, again more clearly revealed Himself in a second birth. For formerly a star in the heavens, now the Father at the waves of Jordan declared Him, and as the Spirit descended upon Him, pouring forth that voice over the head of Him who was baptized, as it follows, And a voice came from heaven, Thou art my beloved Son.