The method and mode of baptism was changed many times over the last 2,000 years. Would you agree with Clements that unless you are baptized you cannot be saved? The Catholic Church held this view right up until Vatican II. And at one time you had to be immerse or baptisted in three times (name of the Father, Son and Holy Ghost). The Church did away with this requirement which is still required in the Orthodox Church. So strongly do the Orthodox feel about the matter that if you leave the Catholic Church and join the Orthodox Church you must be rebaptized.
For when we immerse our heads in water, the old is buried as in a tomb below, and wholly sunk for ever: then as we raise them again, the new man rises in its stead. As it is easy to dip and lift our heads again, so it is easy for God to bury the old man, and to show forth the new. And this is done thrice, that you may learn that the power of the Father, the Son, and the Holy Ghost fulfilleth all things. (St. John Chrysostom, Homilies on St. John, p. 211).
To this very day, the Orthodox still retain the Apostolic pattern, and anybody joining the Orthodox church from the Latin (or most Protestant churches), must be rebaptized the Scriptural way by triune immersion.
Objection 1. It seems that trine immersion is essential to Baptism. For Augustine says in a sermon on the Symbol, addressed to the Neophytes: "Rightly were you dipped three times, since you were baptized in the name of the Trinity. Rightly were you dipped three times, because you were baptized in the name of Jesus Christ, Who on the third day rose again from the dead. For that thrice repeated immersion reproduces the burial of the Lord by which you were buried with Christ in Baptism." Now both seem to be essential to Baptism, namely, that in Baptism the Trinity of Persons should be signified, and that we should be conformed to Christ's burial. Therefore it seems that trine immersion is essential to Baptism. (Catholic Encyclopedia, article on baptism).
Then he quotes Pope Gregory to show that the rite was changed to single immersion by the Spanish Fourth Council of Toledo in 633:
On the contrary, Gregory wrote to the Bishop Leander: "It cannot be in any way reprehensible to baptize an infant with either a trine or a single immersion: since the Trinity can be represented in the three immersions, and the unity of the Godhead in one immersion."
I answer that As stated above (7, ad 1), washing with water is of itself required for Baptism, being essential to the sacrament: whereas the mode of washing is accidental to the sacrament. Consequently, as Gregory in the words above quoted explains, both single and trine immersion are lawful considered in themselves; since one immersion signifies the oneness of Christ's death and of the Godhead; while trine immersion signifies the three days of Christ's burial, and also the Trinity of Persons.
But for various reasons, according as the Church has ordained, one mode has been in practice, at one time, the other at another time. For since from the very earliest days of the Church some have had false notions concerning the Trinity, holding that Christ is a mere man, and that He is not called the "Son of God" or "God" except by reason of His merit, which was chiefly in His death; for this reason they did not baptize in the name of the Trinity, but in memory of Christ's death, and with one immersion. And this was condemned in the early Church. Wherefore in the Apostolic Canons (xlix) we read: "If any priest or bishop confer baptism not with the trine immersion in the one administration, but with one immersion, which baptism is said to be conferred by some in the death of the Lord, let him be deposed": for our Lord did not say, "Baptize ye in My death," but "In the name of the Father and of the Son, and of the Holy Ghost."
Later on, however, there arose the error of certain schismatics and heretics who rebaptized: as Augustine (Super. Joan., cf. De Haeres. lxix) relates of the Donatists. Wherefore, in detestation of their error, only one immersion was ordered to be made, by the (fourth) council of Toledo, in the acts of which we read: "In order to avoid the scandal of schism or the practice of heretical teaching let us hold to the single baptismal immersion."
But now that this motive has ceased, trine immersion is universally observed in Baptism: and consequently anyone baptizing otherwise would sin gravely, through not following the ritual of the Church. It would, however, be valid Baptism.(Catholic Encyclopedia, article on baptism).
The Fourth Council of Toledo changed the mode of baptism
The Fourth Council of Toledo was held in Toledo, Spain, in the year 633. It was not an ecumenical council and no Greeks were present. The Pope at that time was Gregory I, also called Gregory the GREAT.
At that time, the Vatican called anyone who did not belong to their church by the contemptuous title, ARIAN....An ARIAN meant anybody who didn't believe in the Trinity. The Goths of Spain would not unite with the Papacy and they considered themselves to be the true Catholics:
The Arians of Spain commonly referred to Catholicism as "the Roman religion", while Arianism was considered by them to be "the Catholic faith."' To become a Nicaean was, so to speak, to become a Roman, to cease to be a Goth. But they cannot seriously have regarded Arianism as 'catholic': that would have been in contradiction with the use of Gothic as the liturgical language and with the requirement of rebaptism of converts from Catholicism. (Thompson, The Goths in Spain, p. 40).
Now these "ARIAN" Goths in Spain baptized by TRIPLE IMMERSION even though the Roman historians say they didn't believe in the Trinity:
The triple as well as the simple immersion at baptism was recognized by the Catholic Church until it was noticed that the Arians of Spain immersed thrice. In a letter to Leander of Seville, Gregory the Great then recommended the Catholics to immerse once only so as to distinguish themselves from the heretics? (His letter was written in April 591 when Arianism had been smashed, and the need to distinguish Catholic baptismal rites from Arian ones might seem to have been less pressing than it had formerly been.) The problem was a puzzling one: it had already been raised among the Catholics of the Suevic kingdom of Galicia. It had been discussed by Pope Vigilius in 538 in a letter to Profuturus, Metropolitan of Braga,who had asked Rome for a ruling on this and other matters; and Vigilius, unlike his great successor, had declared in favour of the triple immersion. (Thompson, The Goths in Spain, p. 41-42)).
the Scriptures do not tell us a specific mode of baptism is required.
the Scriptures do tell us absolutely baptism is required for salvation.
again, what we don’t find is anywhere the Scriptures teaching us baptism is symbolic, and we don’t find the Catholic Faith as evidenced by the Fathers teaching this either.