Baptism forgives sins, delivers from death and regenerates man

Oh, what a god is this! everywhere perverse; nowhere rational; in all cases vain; and therefore a nonentity!—in whose state, and condition, and nature, and every appointment, I see no coherence and consistency; no, not even in the very sacrament of his faith! For what end does baptism serve, according to him? If the remission of sins, how will he make it evident that he remits sins, when he affords no evidence that he retains them? Because he would retain them, if he performed the functions of a judge. If deliverance from death, how could he deliver from death, who has not delivered to death? For he must have delivered the sinner to death, if he had from the beginning condemned sin. If the regeneration of man, how can he regenerate, who has never generated? For the repetition of an act is impossible to him, by whom nothing any time has been ever done. If the bestowal of the Holy Ghost, how will he bestow the Spirit, who did not at first impart the life? For the life is in a sense the supplement of the Spirit. He therefore seals man, who had never been unsealed in respect of him; washes man, who had never been defiled so far as he was concerned; and into this sacrament of salvation wholly plunges that flesh which is beyond the pale of salvation!

Tertullian
The Five Books Against Marion, Book I
Chapter XXVIII

The sacraments show God’s purpose for the physical world

Indeed, up to the present time, he has not disdained the water which the Creator made wherewith he washes his people; nor the oil with which he anoints them; nor that union of honey and milk wherewithal he gives them the nourishment of children; nor the bread by which he represents his own proper body, thus requiring in his very sacraments the “beggarly elements” of the Creator.

Tertullian
The Five Books Against Marcion, Book I
Chapter XIV

We are taken up from baptism as new-born children

I shall begin with baptism. When we are going to enter the water, but a little before, in the presence of the congregation and under the hand of the president, we solemnly profess that we disown the devil, and his pomp, and his angels. Hereupon we are thrice immersed, making a somewhat ampler pledge than the Lord has appointed in the Gospel. Then when we are taken up (as new-born children), we taste first of all a mixture of milk and honey, and from that day we refrain from the daily bath for a whole week. We take also, in congregations before daybreak, and from the hand of none but the presidents, the sacrament of the Eucharist, which the Lord both commanded to be eaten at meal-times, and enjoined to be taken by all alike.

Tertullian
The Chaplet
Chapter III

Baptism included a rite of exorcism

Lest any one think that we are dealing in mere argumentative subtleties, I shall turn to that highest authority of our “seal” itself. When entering the water, we make profession of the Christian faith in the words of its rule; we bear public testimony that we have renounced the devil, his pomp, and his angels.

Tertullian
The Shows
Chapter IV

Baptism of the Apostles

Yes, truly, the apostles were baptized, as Clement the Stromatist relates in the fifth book of the Hypotyposes. For, in explaining the apostolic statement, I thank God that I baptised none of you, he says, Christ is said to have baptised Peter alone, and Peter Andrew, and Andrew John, and they James and the rest.

St. John Moschus
Spiritual Meadow, Book V
Chapter 176
Quote from lost work of Clement of Alexandria

Exert your will and be saved and initiated in the sacred mysteries

Exert your will only, and you have overcome ruin; bound to the wood of the cross, thou shalt be freed from destruction: the word of God will be thy pilot, and the Holy Spirit will bring thee to anchor in the haven of heaven. Then shalt thou see my God, and be initiated into the sacred mysteries, and come to the fruition of those things which are laid up in heaven reserved for me, which “ear hath not heard, nor have they entered into the heart of any.”

Clement of Alexandria
Exhortation to the Heathen
Chapter XII

Baptism both Water and Word

These are our invulnerable weapons: armed with these, let us face the evil one; “the fiery darts of the evil one” let us quench with the sword-points dipped in water, that, have been baptized by the Word, returning grateful thanks for the benefits we have received, and honoring God through the Divine Word.

Clement of Alexandria
Exhortation to the Heathen
Chapter XI

The Holy Spirit is “water from heaven” and makes all one in Christ

Wherefore also the Lord promised to send the Comforter,3620 who should join us to God. For as a compacted lump of dough cannot be formed of dry wheat without fluid matter, nor can a loaf possess unity, so, in like manner, neither could we, being many, be made one in Christ Jesus without the water from heaven.

Irenaeus of Lyons
Against Heresies, Book III
Chapter XVII

Jesus sanctified humanity having lived the full human experience

For He came to save all through means of Himself—all, I say, who through Him are born again to God—infants, and children, and boys, and youths, and old men. He therefore passed through every age, becoming an infant for infants, thus sanctifying infants; a child for children, thus sanctifying those who are of this age, being at the same time made to them an example of piety, righteousness, and submission; a youth for youths, becoming an example to youths, and thus sanctifying them for the Lord. So likewise He was an old man for old men, that He might be a perfect Master for all, not merely as respects the setting forth of the truth, but also as regards age, sanctifying at the same time the aged also, and becoming an example to them likewise.

Irenaeus of Lyons
Against Heresies, Book II
Chapter XXII