The Father is greater than Jesus of Nazareth, human and vulnerable as any other human. But the Gospel of John Chapter 1 begins with "In the beginning was the Word and the Word was with God and the Word was God. He was with God in the beginning. Through him all things were made that has been made. . ."
And John 10:30 quotes Jesus as saying "I and the Father are one."
I personally don't argue with anyone who thinks the Christ and God are separate beings, but my personal faith is that they and the Holy Spirit are all one and the same other than being three forms/manifestations of the one living God. Just as ice, water, and steam are all three forms/manifestations of H2O.
So for me the issue of which is greater is moot.
What exactly does it mean to be one with God? The scriptures do not express that this means that God and Jesus are the same being. Consider these verses:
John 17:20-24
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:
23 I 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.
In this verse, Jesus is praying to His Father and is praying for all those who believe. He prays that we all may be one even as the Father is one with Jesus. Verse 22 seems to indicate that those who are allowed to share in God's glory can become one with them. If we can all become one even as Jesus is one with the Father, then am I to think that I will become part of the same being? I don't think this what is meant by sharing in the oneness that the Father and Jesus have. I believe the oneness comes to the believer by submitting to the will of the Father just as Jesus perfectly submitted his will to the Father. Once one does this he/she begins to take upon themselves the glory of God and eventually they can be perfected in glory and be one even as the Father and Jesus are one. We can all be separate and distinct beings and yet be one in purpose and unity, sharing in the same glory as that of the Father. Yet as we share in that oneness of will and unity we can become one in mind and will and desire. Thus we can become perfect in one with the Father and Jesus. We don't become the same being. Yet we share in the same oneness that the Father and Jesus share.
John 17:11
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.
If we are to become one even as the Father and Jesus are one, this would mean that we can also become either the same being or we can share in the unity and purpose and will of God. I seriously doubt that we will become the same being. The oneness that Jesus has with the Father is not that they are the same being. They are united in purpose and will. Jesus only did that which the Father would would have him do. He submitted his will to the Father even from before the foundation of the world. This is what we must do (submit our will to the Father until it become our will) in order that we may be one, even as the Father and Jesus are one. The scriptures never teach that the Father and Jesus are the same being.