8 But give me now your best attention, I pray you, for I wish to go back to the fountain of life, and to view the fountain that gushes with healing. The Father of immortality sent the immortal Son and Word into the world, who came to man in order to wash him with water and the Spirit; and He, begetting us again to incorruption of soul and body, breathed into us the breath (spirit) of life, and endued us with an incorruptible panoply. If, therefore, man has become immortal, he will also be God. And if he is made God by water and the Holy Spirit after the regeneration of the layer he is found to be also joint-heir with Christ after the resurrection from the dead.
Wherefore I preach to this effect: Come, all you kindreds of the nations, to the immortality of the baptism. I bring good tidings of life to you who tarry in the darkness of ignorance. Come into liberty from slavery, into a kingdom from tyranny, into incorruption from corruption. And how, says one, shall we come? How? By water and the Holy Ghost. This is the water in conjunction with the Spirit, by which paradise is watered, by which the earth is enriched, by which plants grow, by which animals multiply, and (to sum up the whole in a single word) by which man is begotten again and endued with life, in which also Christ was baptized, and in which the Spirit descended in the form of a dove.
Source: Discourse on the Holy Theophany (New Advent)