The anti-Trinitarian Oneness Pentecostals, especially the United Pentecostal Church International (UPCI), assert that the so-called “apostolic” baptismal formula was a verbal formula, “in the name of Jesus,” recorded in Acts and not in the Trinitarian formula expressed in Matthew 28:19. This position is based on the following assertions:
1) Unitarian Assumption. In order to circumvent and deny the clear Trinitarian formula in Matthew 28:19 and clear Trinitarian implications found in the entirety of the NT content, Oneness believers start with their unitarian/unipersonal premise (viz. God exists as one person) and thus interpret the Bible through those lenses (as Muslims and JWs do).
Response: First, and most obvious, there is no place in the OT or NT where God is described as “one person.” Instead, Scripture clearly defines God as “one Being.” Monotheism is the teaching that God is one Being, not one person. Thus, passages that speak of one God (e.g., Deut. 6:4; Isa. 43:10; Mark 12:29; 1 Tim. 2:5; etc.), Oneness advocates radically re-define monotheism to mean unipersonalism (one person). Second, and what Oneness advocates seem to ignore, in the OT there are many plural nouns, verbs, adjectives, and prepositions describing the one true Yahweh (such as Gen. 1:26; 3:22; 11:7; Isa. 6:8; 54:5 [Heb. “Makers, Husbands”]; Eccl. 12:1 [Heb. “Creators”]; and many more could be exampled). Further, there are places in the OT, where Yahweh interacts with another Yahweh. Note for example, Genesis 19:24: “Then the LORD [Yahweh] rained on Sodom and Gomorrah brimstone and fire from the LORD [Yahweh] out of heaven” (cf. also Dan. 7:9-14; Hosea 1:7).
Even more, the NT clearly presents three distinct divine persons, the Father, and the Son, and the Holy Spirit who share the nature of the one God (cf. Matt. 28:19; Luke 10:21-22; John 1:1; Gal. 1:3; 2 Cor. 13:14; Heb. 1:3, 6, 8-10; 1 Pet. 1:2; 1 John 1:3; Jude 1:20-21; etc.). These passages are only consistent with biblical monotheism in the context of Trinitarianism.
2) In the “Name,” not “Names.” Oneness advocates argue that because the “name” in the passage is singular, the “name” (person) then is Jesus who is the single unipersonal deity behind the masks or roles of the “Father,” “Son,” and “Holy Spirit.”
Response: Grammatically, if the term onoma (“name”) had been written in the plural (onomata, i.e., “in the names”), it would have clearly indicated three separate beings—which is not Trinitarianism. That the singularity of a word necessarily implies absolute solitude is refuted by such passages as Genesis 11:4. Here we read of the people of Babel saying: “Come let us build for ourselves a city, and a tower whose top will reach into heaven, and let us make for ourselves a name….” The “name” here appears in the singular in both the Hebrew (shem) and in the LXX (onoma) being applied to a whole multitude of people—not to one person. Hence, in Matthew 28:19, Jesus commands the apostles to baptize their converts “in the name [not ‘names’] of the Father, and the Son, and the Holy Ghost”—the triune God.
3) “Name”= Power/Authority. The singularity of the term onoma (“name”) in Matthew 28:19 has nothing to do with a singular person, but has everything to do with the Semitic concept of “NAME,”—viz., authority/power person. Many times the term “name” in a Jewish mindset did not merely serve as a designation of a person’s given name (unless the context says otherwise), but rather referred to the essence of the person himself.  The NT import extends back to the OT in such places as the David and Goliath narrative: “You come to me with a sword, a spear and a javelin, but I come to you in the name of the LORD [Yahweh] of hosts, the God of the armies of Israel, whom you have taunted” (1 Sam. 17:45; cf. Acts 4:7). Thus, Christian baptism symbolizes the unification of the new convert into (cf. eis at 1 Cor. 10:2) the “name,” that is, in the power/authority of the one and only true triune God, Yahweh—the Father, and the Son, and the Holy Spirit.
4) Distinct Persons. There are also grammatical reasons refuting the Oneness position of Matthew 28:19. First, the text does not read, “In the name of the Father, Son, and Holy Spirit,” which would give some grammatical (but not contextual) merit to the Oneness position, since the reading contains only one article (“the”) preceding “Father.” Nor is the preposition eis (“in,” or “into”) repeated as, “In the name of the Father and in the Son and in the Holy Spirit,” which can be construed as three separate Beings. Rather, as Matthew wrote: “In the name of the Father, and the Son, and the Holy Spirit” (eis to onoma tou patros kai tou hiou kai tou hagiou).
Second, as established by grammarians and noted biblical scholars (e.g., Sharp,  Warfield, Robertson, Greenlee, Wallace et al), Matthew 28:19 clearly denotes three distinct persons obliterating the “non-distinction of persons” assertion made by Oneness advocates. For the text reads: “In the name of the [tou] Father, and [kai] of the [tou] Son, and [kai] of the [tou] Holy Spirit.” Note that in the Greek, the definite article tou (“the”) precedes each singular personal noun (“Father,” “Son,” “Holy Spirit”) and each noun is connected by the conjunction, kai (“and”).
This construction clearly distinguishes the three persons. There are passages in the NT that also fall under Sharp’s rule #6 distinguishing the persons in the Trinity. Note the literal rendering of these passages below:
- 2 Corinthians 13:14: “The grace of the [tou] Lord Jesus Christ and [kai] the love of the [tou] God and [kai] the fellowship of the [tou] Holy Spirit with all of you.”
- 1 John 1:3: “indeed our fellowship is with the [tou] Father and [kai] with the [tou] Son of Him Jesus Christ.”
- Revelation 5:13: “the [tō] One sitting upon the throne and [kai] to the [tō] Lamb, the blessing and the honor and the glory and the dominion into the ages of the ages.”
See also 1 Thessalonians 3:11; 2 Thessalonians 2:16; and 1 John 2:22-23, which also fall under this construction clearly differentiating Jesus and the Father as two distinct persons. Alongside the aforementioned, there are many passages where all three persons of the Trinity are in apposition (cf. Matt. 3:16-17; Luke 10:21-22; Gal. 4:6; Eph. 2:18; 1 Thess. 1:3-6; 2 Thess. 2:13; Titus 3:5-7; 1 Peter 1:2-3; Jude 1:20-21; etc.).
Which Formula Matthew 28:19 or Acts?
Because the few recorded baptisms in the Acts narrative were “in the name of Jesus” (or a variation), and not in the Trinitarian formula, Oneness advocates argue that the “correct” apostolic “verbal” formula was “in the name of Jesus,” and not in the Trinitarian formula.
Consider this, none of the instances or references of water baptism in Acts exegetically indicate that “in the name of Jesus” was an “audible” verbal pronouncement. Rather, “in the name of Jesus” denoted the type or kind of baptism (i.e., into the power/ authority of Jesus) as shown above. In terms of a verbal formula, I believe they would have been faithful to the Trinitarian pronouncement given by Christ in Matthew 28:19 (as the patristic record shows).
However, even assuming that “in the name of Jesus” was a “verbal” formula utilized in Acts, there is a plausible explanation removing a “Matthew vs. Acts” conflict. Consider that when Jesus gives His disciples the so-called Great Commission in Matthew 28:19, He instructs them to go out into panta ta ethnē (“all the nations”). Many nations were pagan and were involved in worshiping creatures, things in creation, and not the true Creator (cf. Rom. 1:18ff.). Hence, the full revelation of the triune God was at issue.
On the other hand, in Acts, the new converts who were baptized were Jews (cf. 2:5; 22:16), God-fearing Gentiles (cf. 10:1-2, 22, 48) and disciples of John the Baptist (cf. 19:1-5). The new converts that were baptized as recorded in Acts had a prior conception (although incomplete and inaccurate) of God. Thus, in Acts, the emphasis of the baptism was on Jesus Christ (cf. Acts 10:43), and through Him, “there is salvation in no one else; for there is no other name under heaven that has been given among men by which we must be saved” (Acts 4:12).
Lastly, note what the recorded baptisms in Acts actually say. There are at least three “Jesus’ name” formulas stated in Acts: “on [epi + dative] the name of Jesus Christ” (2:38); “into [eis + accusative] the name of the Lord Jesus” (8:16; 19:5); and “in [en + dative] the name of Jesus Christ” (10:48). If in fact these baptisms recorded in Acts were performed by means of a “verbal” baptismal formula and thus mandated to the church, as is supposed by Oneness advocates, then according to the record, the early Christians did not utilize any “exact” verbal formula by which they baptized.
Although both views (the Matthean Trinitarian formula and the so-called “Jesus’ name” verbal formula in Acts) are both theologically possible, the Oneness inept hermeneutic of Matthew 28:19, along with their hyper-dogmatic strict “name” formula, which is required for salvation, sharply opposes the entire theology of both the OT and NT. Thus, one thing is clear: neither the early church nor contemporary scholarship agrees with the Oneness-unitarian position of Matt. 28:19.
Manuscripts and the Early Church: The Trinitarian Formula
Of all the extant Greek manuscripts that contain the ending of Matthew, not one omits the Trinitarian formula and no variant reading exists. Church history is utterly a thorn in the flesh to Oneness theology. Even more, today there exists massive amounts of patristic writings (esp. the apostolic church Fathers) and early documents that quote the full Trinitarian clause of Matthew 28:19 in a Trinitarian context. Within these writings, not one of these early Fathers taught or even implied that a “Jesus’ name” baptismal formula was the “correct” formula and thus essential to one’s salvation, nor did any assert a Oneness interpretation of Matthew 28:19.
Some historically obtuse Oneness believers would erroneously cite a few early church Fathers who have “loosely” (or paraphrased) quoted the passage rendering it as “baptize them in the name of Jesus” or “baptizing them in my name” with no mention of the Trinitarian clause–namely, Eusebius. However, Eusebius, does quote the full Trinitarian formula at least four times, twice in Contra Marcellum, once in De Ecclesiastica Theologia, and once in a letter written to the church at Caesarea. Thus, it is unsound to argue that because a church Father quotes Matthew 28:19 roughly and incomplete omitting the full Trinitarian formula that a denial of the Trinity must be in view.
It is quite easy to demonstrate that early church collectively used the Trinitarian baptismal formula in baptism as Jesus prescribed in Matthew 28:19. For example, the early church instructional manual, the Didache (“teaching,” formally called The Teaching of the Twelve Apostles, c. A.D. 90-120), speaking of water baptism, provides clear instructions in a Trinitarian context alluding to Matthew 28:19:
Now about baptism: this is how to baptize. Give public instruction . . . then “baptize” in running water, “in the name of the Father and of the Son and of the Holy Spirit.” If you do not have running water . . . then pour water on the head three times “in the name of the Father, Son, and Holy Spirit” (7).
Justin Martyr (c. A. D. 155): “For they are then washed in the water in the name of God the Father and Master of all, and of our Savior Jesus Christ, and of the Holy Spirit” (First Apology,61).
Origen (c. A.D. 248): “The Lord himself told his disciples that they should baptize all peoples in the name of the Father and of the Son and of the Holy Spirit … for indeed, legitimate baptism is had only in the name of the Trinity” (Commentary on Romans 5:8).
Cyprian (c. A.D. 250): “‘Go therefore and teach all nations, baptizing them in the name of the Father, the Son, and the Holy Spirit.’ He suggests the Trinity, in whose sacrament the nations were to be baptized.…” (To Jubaianus, Concerning the Baptism of Heretics, LXXII:5, 17-18).
Irenaeus (c. A.D. 190): “We have received baptism … in the name of God the Father, and in the name of Jesus Christ, the Son of God, who was incarnate and died and rose again, and in the Holy Spirit of God” (Demonstration of the Apostolic Preaching, 3).
Many more examples can be cited clearly demonstrating the fact that the baptismal formulaic norm of the early church was decidedly Trinitarian, not modalistic/Oneness. In fact, there are no Christian writings extant from the first several centuries teaching that a strict verbal baptismal formula is necessary for salvation. To say again, the early church collectively and communally utilized the Trinitarian baptismal formula–because they embraced the concept of the Trinity. On this point, patristic authority J. D. N. Kelly points out:
The reader should notice how deeply the conception of a plurality of divine Persons was imprinted in the apostolic tradition and the popular faith.
Oneness-unitarianism is unequivocally non-Christian rejecting the biblical revelation of Jesus Christ. Oneness theology rejects the deity and unipersonality of the Son, it rejects the unipersonality of both the Father and the Holy Spirit, and it rejects the personal distinctions between Jesus and the Father and the Holy Spirit. These rejections constitute a rejection of the very nature of God Himself (cf. Hosea 6:6; John 4:24; 17:3; 1 John 2:22-23).
 Cf. Robert Reymond, Systematic Theology, 226.
 Because of his passionate and unyielding belief in the deity of Jesus Christ, Granville Sharp’s (1735-1813) research in the grammar of the Greek NT led him to discover six grammatical rules in which the Greek article and conjunction were utilized (see Sharp, Remarks on the Uses of the Definite Article in the Greek Text of the New Testament. 3rd. ed. London, UK: Vernor & Hood).
 EIs to onoma tou patros kai tou hiou kai tou hagiou pneumatos.