Is Matthew 28:19 evidence of Trinity baptism?

How do we refute that the Catholic Church changed the way she baptizes from "In Jesus' Name" only to the Trinitarian formula?

I don't think you can refute it. As far as I know, all of the evidence indicates that baptism was in the name of Jesus until the time of Justin Martyr in the mid 2nd century when the Trinity doctrine was invented. Whenever baptism is mentioned in the Bible, it is ALWAYS in the name of Jesus. NONE of the writings of the early church fathers prior to Justin Martyr around A.D. 150 taught Trinity baptism.

BRITANICA ENCYCLOPEDIA – Everywhere in the oldest sources it states that baptism took place in the name of Jesus Christ. Vol. 3, page 82.

As far as the Didache quote that someone posted, scholars are not in agreement regarding the date of the Didache. It may not have been written until after the Trinity doctrine was invented in the second century. Even if it was written earlier, there is evidence that the baptism passage was changed from Jesus only to the Trinity. In another section of the Didache, on the Eucharist, it says a person must be baptized "into the name of the Lord" to receive the Eucharist. I would not consider the Didache to be reliable evidence of Trinity baptism in the early church.

"But let no one eat or drink of your Thanksgiving (Eucharist), but they who have been baptized into the name of the Lord (Didache, Ch. 10)"

Is Matthew 28:19 evidence of Trinity baptism?

“according to a wide scholarly consensus, it is not an authentic saying of Jesus, not even an elaboration of a Jesus-saying on baptism." (The Anchor Bible Dictionary, Vol. 1, 1992, page 585)

“In place of the words "baptizing... Spirit" we should probably read simply "into my name," (Peake's Commentary on the Bible, 1929, page 723).”

“It has been customary to trace the institution of the practice (of baptism) to the words of Christ recorded in Matthew 28:19. But the authenticity of this passage has been challenged on historical as well as on textual grounds. It must be acknowledged that the formula of the threefold name, which is here enjoined, does not appear to have been employed by the primitive Church, which, so far as our information goes, baptized 'in' or 'into the name of Jesus' (The Dictionary of the Bible, 1947, page 83)”

“Critical scholarship, on the whole, rejects the traditional attribution of the tripartite baptismal formula to Jesus and regards it as of later origin. (The Philosophy of the Church Fathers, Vol. 1, Harry Austryn Wolfson, 1964, pg 143)”

"It is often affirmed that the words in the name of the Father, and of the Son, and of the Holy Ghost are not the ipsissima verba [exact words] of Jesus, but...a later liturgical addition. (The Tyndale New Testament Commentaries, I, 275)"

"The testimony for the wide distribution of the simple baptismal formula [in the Name of Jesus] down into the second century is so overwhelming that even in Matthew 28:19, the Trinitarian formula was later inserted. (Wilhelm Bousset, Kyrios Christianity, page 295)"

“the formal authenticity of Matt. 28:19 must be disputed (The Schaff-Herzog Encyclopedia of Religious Knowledge)”

“Matthew 28:19 in particular only canonizes a later ecclesiastical situation, that its universalism is contrary to the facts of early Christian history, and its Trinitarian formula (is) foreign to the mouth of Jesus. (The International Standard Bible Encyclopedia, Vol. 4, page 2637, Baptism)”

Here's how the well respected church historian Eusebius quoted Matthew 28:19 in his writings before Constantine established the Trinity at the Council of Nicea:

"Whereas He, who conceived nothing human or mortal, see how truly he speaks with the voice of God, saying in these very words to those disciples of His, the poorest of the poor : ’Go forth, and make disciples of all the nations.’ ‘But how,’ the disciples might reasonably have answered the Master, ‘can we do it?’… But while the disciples of Jesus were most likely either saying thus, or thinking thus, the Master solved their difficulties, by the addition of one phrase, saying they should triumph ‘IN MY NAME.’ For He did not bid them simply and indefinitely 'make disciples of all nations,' but with the necessary addition 'In My Name.' And the power of His Name being so great, that the Apostle says: 'God has given him a name which is above every name, that in the name of Jesus every knee should bow, of things in heaven, and things in earth, and things under the earth.' He shewed the virtue of the power in His Name concealed from the crowd, when He said to His Disciples: 'Go, and make disciples of all nations in my name.'

Source - The Proof of the Gospel, Vol. 1, edited and translated by W.J. Ferrar, 1981, page 157

Why does Eusebius's quote matter? It matters because ALL known manuscripts of Matthew prior to A.D. 325 when Constantine established the Trinity doctrine are conveniently missing the last page, the page that would have contained Matt 28:19. I don't know whether they were burned to get rid of the original version, but what's known is there is NO biblical evidence that Jesus taught Trinity baptism since there aren't any other verses in the Bible that teach baptism in the name of a Trinity. In fact, they teach the opposite, that baptism was done in the name of Jesus.

There is also textual evidence against Matt 28:19. Which version do you think sounds authentic?

Matthew 28:18-19, Quoted by Eusebius in early 4th Century (A.D. 320)
Jesus said, “All authority … has been given to me. Therefore go and make disciples of all nations in my name…”

Matthew 28:18-19 (NIV), Current Version dated from late 4th Century (A.D. 390)
Jesus said, “All authority … has been given to me. Therefore go and make disciples of all nations, baptizing them in the name of the Father and of the Son and of the Holy Spirit…”

Why would Jesus, after announcing that all authority has been given to him, then say that, because of his authority, his disciples should baptize in someone else's name?

Don't think Matthew 28:19 could have been changed to support the new Catholic Trinity teaching? Research 1John 5:7, the other verse used to support the Trinity. The evidence is so overwhelming that it was added to the Bible, that it has been removed from all modern non-Catholic Bibles.

Unlike the modern Catholic Church, early Christians always did everything in the name of Jesus, and NEVER in the name of a Trinity.

“God greatly exalted him and bestowed on him the name that is above every name, that at the name of Jesus every knee should bend, of those in heaven and on earth and under the earth, and every tongue confess that Jesus Christ is Lord, to the glory of God the Father. (Phillipians 2:9-11, NAB)”

“giving thanks always and for everything in the name of our Lord Jesus Christ to God the Father (Ephesians 5:20, NAB)”

“And whatever you do, in word or in deed, do everything in the name of the Lord Jesus, giving thanks to God the Father through him (Colossians 3:17, NAB)”

I think everything includes baptism.

*St. Paul (Acts 19) commands some disciples at Ephesus to be baptized in Christ's name: "They were baptized in the name of the Lord Jesus*." In Acts 10, we read that St. Peter ordered others to be baptized "in the name of the Lord Jesus Christ". Those who were converted by Philip. (Acts 8) "were baptized in the name of Jesus Christ", and above all we have the explicit command of the Prince of the Apostles: "Be baptized every one of you in the name of Jesus Christ, for the remission of your sins (Acts 2). Source - newadvent.org/cathen/02258b.htm Catholic

The representative of Satan

The apostle Paul, in his second letter to the Thessalonians, foretold the great apostasy which would result in the establishment of the papal power. He declared that the day of Christ should not come, “except there come a falling away first, and that man of sin be revealed, the son of perdition; who opposeth and exalteth himself above all that is called God, or that is worshiped; so that he as God sitteth in the temple of God, showing himself that he is God.” [2 Thessalonians 2:3, 4, 7.] And furthermore, the apostle warns his brethren that “the mystery of iniquity doth already work.” [2 Thessalonians 2:3, 4, 7.] Even at that early date he saw, creeping into the church, errors that would prepare the way for the development of the papacy. 

Little by little, at first in stealth and silence, and then more openly as it increased in strength and gained control of the minds of men, the mystery of iniquity carried forward its deceptive and blasphemous work. Almost imperceptibly the customs of heathenism found their way into the Christian church. The spirit of compromise and conformity was restrained for a time by the fierce persecutions which the church endured under paganism. But as persecution ceased, and Christianity entered the courts and palaces of kings, she laid aside the humble simplicity of Christ and his apostles for the pomp and pride of pagan priests and rulers; and in place of the requirements of God, she substituted human theories and traditions. The nominal conversion of Constantine, in the early part of the fourth century, caused great rejoicing; and the world, cloaked with a form of righteousness, walked into the church. Now the work of corruption rapidly progressed. Paganism, while appearing to be vanquished, became the conqueror. Her spirit controlled the church. Her doctrines, ceremonies, and superstitions were incorporated into the faith and worship of the professed followers of Christ.  

This compromise between paganism and Christianity resulted in the development of the “man of sin” foretold in prophecy as opposing and exalting himself above God. That gigantic system of false religion is a masterpiece of Satan's power,—a monument of his efforts to seat himself upon the throne to rule the earth according to his will.  

Satan once endeavored to form a compromise with Christ. He came to the Son of God in the wilderness of temptation, and, showing him all the kingdoms of the world and the glory of them, offered to give all into his hands if he would but acknowledge the supremacy of the prince of darkness. Christ rebuked the presumptuous tempter, and forced him to depart. But Satan meets with greater success in presenting the same temptations to man. To secure worldly gains and honors, the church was led to seek the favor and support of the great men of earth, and having thus rejected Christ, she was induced to yield allegiance to the representative of Satan,—the bishop of Rome.  

It is one of the leading doctrines of Romanism that the pope is the visible head of the universal church of Christ, invested with supreme authority over bishops and pastors in all parts of the world. More than this, the pope has arrogated the very titles of Deity. He styles himself “Lord God the Pope,” assumes infallibility, and demands that all men pay him homage. Thus the same claim urged by Satan in the wilderness of temptation is still urged by him through the Church of Rome, and vast numbers are ready to yield him homage.  

But those who fear and reverence God meet this Heaven-daring assumption as Christ met the solicitations of the wily foe: “Thou shalt worship the Lord thy God, and him only shalt thou serve.” [Luke 4:8.] God has never given a hint in his Word that he has appointed any man to be the head of the church. The doctrine of papal supremacy is directly opposed to the teachings of the Scriptures. The pope can have no power over Christ's church except by usurpation.  

Romanists have persisted in bringing against Protestants the charge of heresy, and willful separation from the true church. But these accusations apply rather to themselves. They are the ones who laid down the banner of Christ, and departed from “the faith which was once delivered unto the saints.” [Jude 3.]                GC88 50,51.

What Did Arius Really Believe?