Origen's Homilies on Luke Available at Google Books

Yes indeed I finally found that passage which proves the Marcionite gospel had references from John. In the Homilies on Luke we read that the Marcionites interpret the passage:

"sitting at the Savior's right and left" (Matt. 20.21) applies to Paul and Marcion: Paul sits at his right hand and Marcion at his left. Others read the passage, 'I will send you an advocate, the Spirit of Truth' (Jn. 14.16-17) and are unwilling to understand a third person beside the Father and the Son, a divine and exalted nature. They take it to mean the apostle Paul." [Origen Homily on Luke 25]

Oh my God, these people posing as scholars just don't get it, do they? How could the Marcionites NOT have used a super gospel - a version of the Diatessaron - if these two references don't appear in Luke? How do these 'experts' explain this passage? Is Origen lying? Is this another example of a modern scholar 'forging' an ancient text like To Theodore?

Their whole system of over dependence on the 'authority' of the Church Fathers and taking what they say uncritically falls completely to the ground.

The Marcionites used a version of the Diatessaron. There is no other explanation and I have a surprise for these blind guides. There is a surviving Marcionite text from the Marcionite center of Osroene with explicit reference to this second idea - viz. 'Paul as Paraclete.'

The text is the Acts of Archelaus and the main character who rules over the community at Harran is named Marcion (or if you prefer its Latin equivalent 'Marcellus' viz. 'little Mark').

What the hell is the matter with scholars? Do you know I got into a debate with a modern translator of the Acts of Archelaus because he couldn't believe the Marcionites thought that Paul was the Paraclete. 'But they only used Luke,' he told me. My God ...

Anyway here are some of those exciting references from the Acts of Archelaus. The bishop of Harran, Archelaus (the man who serves 'Marcion') declares:

for our Lord Jesus Christ says of this Paraclete, He shall receive of mine. Him therefore He selected as an acceptable vessel; and He sent this Paul to us [AA 34]

the Paraclete, could not come into any other, but could only come upon ... the sainted Paul. For he is a chosen vessel, He says, unto me, to bear my name before kings and the Gentiles. The apostle himself, too, states the same thing in his first epistle, where he says: According to the grace that is given to me of God, that I should be the minister of Jesus Christ to the Gentiles, ministering the Gospel of God. I say the truth in Christ, I lie not, my conscience also bearing me witness in the Holy Ghost. And again: For I will not dare to speak of any of those things which Christ has not wrought by me by word and deed. I am the last of all the apostles, that am not meet to be called an apostle. But by the grace of God I am what I am. And it, is his wish to have to deal with those who sought the proof of that Christ who spoke in him, for this reason, that the Paraclete was in him: and as having obtained His gift of grace, and as being enriched with magnificent, honour, he says: For this thing I besought the Lord thrice, that it might depart from me. And He said unto me, My grace is sufficient for you; for strength is made perfect in weakness. Again, that it was the Paraclete Himself who was in Paul, is indicated by our Lord Jesus Christ in the Gospel, when He says: If you love me, keep my commandments. And I will pray my Father, and He shall give you another Comforter. In these words He points to the Paraclete Himself, for He speaks of another Comforter. And hence we have given credit to Paul, and have hearkened to him when he says, Or do you seek a proof of Christ speaking in me? and when he expresses himself in similar terms, of which we have already spoken above. [AA 35]

I don't need to go on and on. I think the reader gets the point. However what may surprise the reader is that the Coptic history of St. Severus identifies this 'Marcion' (Marcellus) as belonging to the Alexandrian tradition and being symbolically seated on a throne which the heretic Mani wanted to usurp. More on that next time ...