Gregory_PalamasJesus, when He was baptized, went up straightway out of the water:

and, lo, the heavens were opened unto Him, and He saw the Spirit of God descending like a dove, and lighting upon Him:

and lo, a voice from heaven, saying, This is my beloved Son, in whom I am well pleased (Matthew 3:16-17).

Man is the only creature who, in the image of the tri-hypostatic Being, has a mind, reason, and a spirit which gives life to his body, inasmuch as he also has a body which needs to be infused with life.

When our nature was re-made in the Jordan, the most sublime and all-accomplishing Trinity was made manifest, as the archetype of the image in our soul.

[…] Christ’s going down into the water and His being underneath it, at the time of His baptism, foreshadowed His descent into Hades; and, accordingly, His coming up from under the water prefigured His resurrection from the dead.

As a fitting consequence, when He came up from the water the heavens were immediately opened unto Him.

For at the time of His descent into Hades, He went under the earth for our sake, and on returning thence, He opened all things both to Himself and to us, not just things on or around the earth, but highest heaven itself, to which afterwards He ascended bodily, “whither the forerunner is for us entered” (Hebrews 6.20).

Just as He foreshadowed the saving Passion through the mystical bread and cup, and then handed on this mystery to the faithful to perform for their salvation (1 Corinthians 11.25; Luke 22.17-20), so He mystically foretold His descent into Hades and His ascent from there through this baptism of His, and afterwards passed on this sacrament to believers to perform that they may be saved.

He allowed Himself what was painful and difficult, but bestowed on us communion in His sufferings right from the start through these painless means, causing us, according to the Apostle, to be “planted together in the likeness of His death” (Romans 6.5), that in due time we might also be vouchsafed the promised resurrection.

Having a soul and body like ours, which He assumed from us for our sake, by means of this body He underwent the Passion, death and burial for us, and showed forth the resurrection from the tomb that this same body might become immortal.

He taught us to accomplish the bloodless sacrifice in remembrance of these events, that through it we might reap salvation.

With His soul He went down to Hades and returned, making us all partakers in eternal light and life, and in token of this He handed on to us the practice of holy baptism, that through it we might harvest salvation;

and indeed that through each of these two mysteries and through both elements, soul and body, we might be initiated into and receive the seeds of incorruptible life.

For our whole salvation depends on these two sacraments, as the entire dispensation whereby God became man is summed up in them.

Gregory Palamas (1296-1359): Homily 60, on the Holy Feast of Theophany: Disclosing the Mystery of Christ’s Baptism as far as is Possible. From Saint Gregory Palamas: The Homilies (Mount Thabor Publishing, 2009) @ Greek Orthodox Cathedral of the Ascension, Oakland, California.