Matthew 28:19 & trinity, Is it a valid proof ?

"Go therefore and make disciples of all the nations, baptizing them in the name of the Father and the Son and the Holy Spirit" (Matthew 28:19);
Does this not prove that the `Doctrine of Trinity' and its present day formula was communicated and promulgated in the bible ?

With all due respect, we tend to disagree in view of the following compelling evidences:-

1. `Peake's Commentary on the Bible' published since 1919, is universally welcomed and considered to be the standard reference book for the students of the Bible. Commenting on the above verse it records;

"This mission is described in the language of the church and most commentators doubt that the trinitarian formula was original at this point in Mt.'s Gospel, since the NT elsewhere does not know of such a formula and describes baptism as being performed in the name of the Lord Jesus (e.g. Ac. 2:38, 8:16, etc.)."

2. Tom Harpur, author of several bestsellers and a former professor of New Testament, writes in his book `For Christ's Sake';
 

"All but the most conservative of scholars agree that at least the latter part of this command was inserted later. The formula occurs nowhere else in the New Testament, and we know from the only evidence available (the rest of the New Testament) that the earliest Church did not baptise people using these words - baptism was "into" or "in" the name of Jesus alone."

3. Early Christians, such as scholars and historians (up to 350 years after Jesus’ departure), in their writings, and when quoting Matthew 28:19, give a different text than what we have today.

For example, when the Christian historian Eusebius of Caesarea (a.k.a. Eusebius Pamphili) (c. AD 263 – 339), who’s called “Father of Church History,” quoted Matthew 28:19 in his famous Ecclesiastical History, there was no triune formula in the verse.

The verse read,
 

“Go ye and make disciples of all the nations in my name, teaching them to observe all things, whatsoever I commanded you.”

He did not quote this verse in this form only once, but no less than 18 times in many of his works written between 300 and 336, namely in his long commentaries on the Psalms, on Isaiah, in his Demonstratio Evangelica and in his Theophany.

4. The quoted verse (irrespective of it being authentic or otherwise), does not indicate that the three names mentioned are “co-equal” in their status and were also “co-eternal” in the time frame. Unless these two important qualifications are acknowledged, the verse fails to endorse the fundamental belief and principle of the ‘Doctrine of Trinity’.Regardless of all that, there is nothing in the text which indicates that the Father, the Son and the Holy Ghost are one.Regardless of all that, there is nothing in the text which indicates that the Father, the Son and the Holy Ghost are one. The verse talks about three different essences mentioned together in conjunction, which indicates that they are different, distinct essences.


5. If the Father and His Son were both in "existence" from the Day One, and no one was, a micro second before or after, and, no one was "greater or lesser" in status, than why is one called the Father and the other His begotten Son?

6. Did the act of "Begetting" take place? If YES, where was the "Begotten Son" before the act? If NO, why call him the "Begotten Son"?

7.
The Encyclopedia of Religion and Ethics:
As to Matthew 28:19, it says: It is the central piece of evidence for the traditional (Trinitarian) view. If it were undisputed, this would, of course, be decisive, but its trustworthiness is impugned on grounds of textual criticism, literary criticism and historical criticism. The same Encyclopedia further states that: "The obvious explanation of the silence of the New Testament on the triune name, and the use of another (JESUS NAME) formula in Acts and Paul, is that this other formula was the earlier, and the triune formula is a later addition."

Edmund Schlink, The Doctrine of Baptism, page 28:
"The baptismal command in its Matthew 28:19 form can not be the historical origin of Christian baptism. At the very least, it must be assumed that the text has been transmitted in a form expanded by the [Catholic] church."

The Tyndale New Testament Commentaries, I, 275:
"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."

Wilhelm Bousset, Kyrios Christianity, page 295:
"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."

The Catholic Encyclopedia, II, page 263:
"The baptismal formula was changed from the name of Jesus Christ to the words Father, Son, and Holy Spirit by the Catholic Church in the second century."

8. If the US president told someone "Go ye therefore, and speak to the Iraqis, chastising them in the name of the United States, Great Britain, and the Soviet Union," does this require that these three countries are one physical country? They may be one in purpose and in their goals but this does in no way require that they are the same physical entity.
If we assumed it's in the original text, we need to read this hint:
De 18:20  But the prophet, which shall presume to speak a word in my name, which I have not commanded him to speak, or that shall speak in the name of other gods, even that prophet shall die.