Go therefore and make disciples of all nations, baptising them in the name of the Father, and of the Son, and of the Holy Ghost. (Matt 28:19)
This verse has often been used as definitive “proof” of creedal Trinitarianism. Trinitarian apologist, Sam Shamoun, offers the following interpretation:
Noted Bible expositor, the late John Gill, commented on the implications and significance the Trinitarian formula has on the doctrine of the blessed Trinity:
In the name of the Father, and of the Son, and of the Holy Ghost;
by the authority of these three divine persons, who all appeared, and testified their approbation of the administration of this ordinance, at the baptism of Christ: and as they are to be invocated in it, so the persons baptized not only profess faith in each divine person, but are devoted to their service, and worship, and are laid under obligation to obedience to them, Hence a confirmation of the doctrine of the Trinity, there are three persons, but one name, but one God, into which believers are baptized; and a proof of the true deity both of the Son, and of the Holy Ghost; and that Christ, as the Son of God, is God; since baptism is administered equally in the name of all three, as a religious ordinance, a part of divine instituted worship, which would never be in the name of a creature. This is the first, and indeed the only, place in which the Trinity of persons is expressed in this order, and in the selfsame words…
There are many problems with this eisegetical approach to scripture. However, before I begin, let me note that one argument that should not be used, viz. that this verse is a later interpolation. To quote from the corresponding note in the NET Bible:
Although some scholars have denied that the trinitarian baptismal formula in the Great Commission was a part of the original text of Matthew, there is no ms support for their contention. F. C. Conybeare, "The Eusebian Form of the Text of Mat 28:19, " ZNW 2 (1901): 275-88, based his view on a faulty reading of Eusebius' quotations of this text. The shorter reading has also been accepted, on other grounds, by a few other scholars. For discussion (and refutation of the conjecture that removes this baptismal formula), see B. J. Hubbard, The Matthean Redaction of a Primitive Apostolic Commissioning (SBLDS 19), 163–64, 167–75; and Jane Schaberg, The Father, the Son, and the Holy Spirit (SBLDS 61), 27–29.
Shamoun's article, linked above, also does a decent job supporting the authenticity of this verse.
Now, we shall proceed with an examination of the evidence against any pro-Trinitarian implications of this verse:
Firstly, there is no mention or hint of the Father, Son, and Holy Ghost , as a whole and/or individually, being numerically identical to the “one God.” That is something that must be read into this verse (eisegesis). Verse 18 should be the verse that controls the exegetical possibilities one can derive from this baptismal formula, as Jesus, even after the ascension and his exaltation by the Father (cf. Phil 2:5-11), states that "All power is given unto me in heaven and earth," showing it was not intrinsically His prior to such (clearly supporting a form of subordinationist Christology). One should also see John 20:17 and the Christology of the Epistle to the Hebrews, including Heb 1:8-9, where there is a God above Jesus, notwithstanding his exalted state.
Secondly, notwithstanding the apologists’ use of “name” (ονομα) being singular, this poses no problem for Latter-day Saint theology. “Name” in the Old and New Testaments often meant one’s “title” (as in Isa 9:6) and/or the power and authority one possessed./acted under. Consider, just as one of many examples, John 5:43, a saying of Jesus Himself:
I am come in my Father's name, and ye receive me not: if another shall come in his own name, him ye will receive.
Just as Christ in this verse comes in his Father's "name" (i.e., authority), so also his followers baptise by the authority of the Father, Son, and Holy Spirit, which is a single authority and power.
A related passage would be John 17:26:
And I have declared unto them thy name, and I will declare it; that the love wherewith thou hast loved me may be in them, and I in them (cf. 2 Sam 8:13; Isa 55:13; Jer 13:11 Ezek 22:5; Rev 3:2).
Richard Hopkins, in his book, Biblical Mormonism (Horizon, 1994), offered an alternative approach to this verse, viz. that the singular form of the word "name" is correctly used to shorten the passage from "in the name of the Father, and in the name of the Son, and in the name of the Holy Ghost." Hopkins further argued that, if the plural form were used, it would signify that the passage had been shorted from "in the names of the Father, and in the names of the Son, and in the names of the Holy Ghost." Therefore, the use of the singular is proper where each person is designated in the phrase has His own name (Hopkins, p. 79). While I don't accept this interpretation, it is not an impossible reading of the evidence.
Taking a prima facie and even secunda facie reading of this verse, it clearly presents the Father, Son, and Spirit as three separate persons in the normative understanding of that term, not the later post-biblical theories about the distinction between the persons of the Tri-une God. If anything, this would support, not creedal Trinitarianism, but Social Trinitarianism, which allows for the Father, Son, and Spirit to be three separate persons in the proper meaning of the term, with their own centre of consciousness, as advanced by the likes of Richard Swinburne. For a book-length treatment on the issue of “person” in Trinitarian circles, see Persons: Human and Divine (Oxford University Press, 2007), eds. Peter Van Inwagen and Dean Zimmerman.
It should also be noted that, since the beginning of the Church, Latter-day Saint baptism is performed using the same formula; note D&C 20:73:
The person who is called of God and has authority from Jesus Christ to baptise, shall go down into the water with the person who has presented himself or herself for baptism, and shall say, calling him or her by name: Having been commissioned of Jesus Christ, I baptise you in the name of the Father, and of the Son, and of the Holy Ghost. Amen.
This is the same formula I was baptised under. Furthermore, such a phrase appears in the current (1985) LDS hymnal, such as “Arise, O God, and Shine,” with the final stanza reading (emphasis added):
To God, the only wise. The one immortal King, let hallelujahs rise from ev'ry living thing: let all that breathe, on ev'ry coast, praise Father, Son, and Holy Ghost.
Many Trinitarian apologists are much more cautious about using the baptismal formula as positive evidence for the Trinity, in contrast to Shamoun, Gill, Robert Bowman, Ron Rhodes, and others. JP Holding, a critic of the LDS faith, writes:
I would begin by noting that our own study of the Trinity makes absolutely no use of Matthew 28:19. This verse is not particularly useful for Trinitarian defense as it theoretically could support any view -- modalism, even tritheism, could be permitted from this verse, for it only lists the members of the Triune Godhead with absolutely no explanation as to their exact relationship.
Verse 18 would indicate that the Father is in a functionally superior relationship to the Son, but that says nothing about an ontological relationship; though one may justly argue that it is very unlikely (but not impossible) that all three would be named together if there were not an ontological equality, lest God's glory somehow be compromised.
None of the earliest commentators on this verse (e.g., Tertullian; Ignatius of Antioch; Origen) ever used the verse to support the concept of metaphysical “oneness” of the Father, Son, and Spirit; such is a later development in the Christian interpretative tradition.
While other important points could be raised, I will discuss just one more--in reality, the Trinitarian apologists who appeal to Matt 28:19 are guilty of question begging. Simply because a verse or pericope has the three persons of the Godhead together, that is definitive “proof” of their co-equality, co-eternality, and all other elements required for creedal Trinitarianism. However, triads appear all throughout the New Testament, and yet, there is often an explication of one of the members being superior to the other two, showing that a triad, in and of itself, is insufficient to cite for evidence of co-equality.
For instance, in 1 Cor 13:13, we read:
And now abideth faith, hope, charity, these three; but the greatest of these is charity.
Just because faith, hope, and love (KJV: charity) are in a triadic proximity to one another, similar to the Father, Son, and Spirit in Matt 28:19, such does not prove ontological equality since one of these is said to be the greatest; this should, at the very least, force one to be very cautious to present this verse as positive evidence of Trinitarian theology.
If one wishes to absolutise Matt 28:19, within a Trinitarian hermeneutic, such would cause all sorts of problems with one's exegesis and theology. Note 1 John 5:8:
One would have to conclude, based on the interpretive framework many Trinitarian apologists employ, that this shows that the Trinity is composed of Spirit, water, and blood. In reality, in this verse, and in Matt 28:19, there is no triune being/entity in view here.
If one wishes to absolutise Matt 28:19, within a Trinitarian hermeneutic, such would cause all sorts of problems with one's exegesis and theology. Note 1 John 5:8:
There are three that testify: the Spirit and the Water and the blood, and these three agree (NRSV).
One would have to conclude, based on the interpretive framework many Trinitarian apologists employ, that this shows that the Trinity is composed of Spirit, water, and blood. In reality, in this verse, and in Matt 28:19, there is no triune being/entity in view here.
Indeed, the early Christians, such as Tertullian, used triadic language, but when one examines the totality of their writings, they did not hold to modern Trinitarian theology and thought. In the case of Tertullian, we find that he did not believe Jesus eternally pre-existed and that "spirit" was material, a rejection of "divine simplicity," a necessary element in later Trinitarian theologies.
For sound, scholarly discussions, see:
Marian Hillar, From Logos to Trinity: The Evolution of Religious Beliefs from Pythagoras to Tertullian (Cambridge University Press, 2012)
Thomas Gaston, “Proto-Trinity: The Development of the Doctrine of the Trinity in the First and Second Christian Centuries” (M.Lit Dissertation: University of Birmingham, 2007); available online.
I would also suggest, albeit cautiously, J. Gwyn Giffiths, Triads and Trinity (University of Wales Press, 1996). Alvin Lamson, The Church of the First Three Centuries (1860) is also an important, though somewhat dated, volume (available online here).
If one reads the writings of other early Christian authors, one will find something similar. Justin Martyr, for example, enumerates God, Jesus, and the Holy Spirit as three things, but uses ordinals (first, second, third), a clear hierarchy (First Apology, 13). Irenaeus of Lyons treated God, Jesus, and the Spirit as three articles of faith, but never calls the Spirit "Lord" (κυριος) (Demonstration, 7), showing that the Christologies of early Christianity were subordinationist in nature. Again, such is definitive evidence against creedal Trinitarianism being reflective of the earliest theologies of Christianity. It is a later, man-made development.
While much more could be said, it is evident from the above that Trinitarian apologists who employ Matt 28:19 so support their theology are on an exegetical fishing trip and have no fishing poles.