John 17 (KJV)
1 These words spake Jesus, and lifted up his eyes to heaven, and said, Father, the hour is come; glorify thy Son, that thy Son also may glorify thee:
This is one person (individual) speaking to another person (individual) reciprocating glory / glorification. This is not two phases of the same individual (person). To glorify one another means there has to be another (more than one). This is not spiritual Marco Polo.
2 As thou hast given him power over all flesh, that he should give eternal life to as many as thou hast given him.
Here Jesus speaks in the third person but still refers to the Father as a distinct individual other than the third party he is speaking in. This is not a "let us create in our image and our likeness" statement. He maintains the Father's distinctiveness... if he Jesus were the Father he would have stepped into the role of the Father in speech at this point.
3 And this is life eternal, that they might know thee the only true God, and Jesus Christ, whom thou hast sent.
Jesus here is not undeifying himself. He is further establishing the distinction between himself and the Father; especially in nature since Jesus has two natures (physical and spiritual). His Spirit is divine (Colossians 2:9). He is saying that there is more to Jesus than simply being God the Word (John 1:1, John 1:14, Philippians 2:6 in Greek: morphe theos huparchon never ceasing to be God he became a man...)
4 I have glorified thee on the earth: I have finished the work which thou gavest me to do.
He did not say I glorified myself or myself in another form
He did not say I have finished my work or my work in another form
He did say that it was given him to do... by another individual than himself
5 And now, O Father, glorify thou me with thine own self with the glory which I had with thee before the world was.
He did not call upon a past form of himself to make the present form of himself like the past form of himself who was with that past form of himself somehow... Clearly Oneness theology makes not sense and conflicts with scripture.
6 I have manifested thy name unto the men which thou gavest me out of the world: thine they were, and thou gavest them me; and they have kept thy word.
The name YHVH... YHVH Shua (Salvation of YHVH) which is Jesus' name. But Jesus name is YHVH Saves.
7 Now they have known that all things whatsoever thou hast given me are of thee.
Everything about this prayer is distinction between two individuals of deity (one of which is also human).
8 For I have given unto them the words which thou gavest me; and they have received them, and have known surely that I came out from thee, and they have believed that thou didst send me.
ibid
9 I pray for them: I pray not for the world, but for them which thou hast given me; for they are thine.
10 And all mine are thine, and thine are mine; and I am glorified in them.
11 And now I am no more in the world, but these are in the world, and I come to thee. Holy Father, keep through thine own name those whom thou hast given me, that they may be one, as we are.
Here is the biblical example and definition of plurality in the Godhead because we individuals in then Church are more than one person...
12 While I was with them in the world, I kept them in thy name: those that thou gavest me I have kept, and none of them is lost, but the son of perdition; that the scripture might be fulfilled.
13 And now come I to thee; and these things I speak in the world, that they might have my joy fulfilled in themselves.
14 I have given them thy word; and the world hath hated them, because they are not of the world, even as I am not of the world.
15 I pray not that thou shouldest take them out of the world, but that thou shouldest keep them from the evil.
16 They are not of the world, even as I am not of the world.
17 Sanctify them through thy truth: thy word is truth.
18 As thou hast sent me into the world, even so have I also sent them into the world.
19 And for their sakes I sanctify myself, that they also might be sanctified through the truth.
Christian sanc***y / justification to enable us to do the works of God once we are saved (procured that sanctification).
20 Neither pray I for these alone, but for them also which shall believe on me through their word;
21 That they all may be one; as thou, Father, art in me, and I in thee, that they also may be one in us: that the world may believe that thou hast sent me.
22 And the glory which thou gavest me I have given them; that they may be one, even as we are one:
23I in them, and thou in me, that they may be made perfect in one; and that the world may know that thou hast sent me, and hast loved them, as thou hast loved me.
24 Father, I will that they also, whom thou hast given me, be with me where I am; that they may behold my glory, which thou hast given me: for thou lovedst me before the foundation of the world.
25 O righteous Father, the world hath not known thee: but I have known thee, and these have known that thou hast sent me.
Curious statement if Oneness modalism is true.
26 And I have declared unto them thy name, and will declare it: that the love wherewith thou hast loved me may be in them, and I in them.