CLAIM: Critics of the Trinity point out that Jesus said, “The Father is greater than I” (Jn. 14:28). How can Jesus say this, if he was equally God?
RESPONSE: Jesus was equal with God in nature, but not in office (1 Cor. 11:3). Jesus submitted to the will of the Father, rather than asserting his own will (Lk. 22:42). Similarly, while a human father and son are both human in nature, they are not equal in authority or office. James White writes,
Why would the disciples rejoice because Jesus was going to see a being who is greater than He? Why would that cause rejoicing? But the term does not refer to ‘better’ but ‘greater’ as in positionally greater.
In context, Jesus is leaving to go be with the Father, and he is leaving the horrors of living on the Earth. While he humbled himself at the incarnation, this was soon going to end. He was going to be with God in heaven. That is, when read in context, we see that Jesus is referring to going back to be with the Father in heaven, and he is leaving Earth. Later in the book, he says, “Father, glorify Me together with Yourself, with the glory which I had with You before the world was” (Jn. 17:5). In other words, Jesus is looking forward to going back to being with God in heaven, as the context dictates. For more on this subject, see our earlier articles “Defending the Deity of Christ” and “Defending the Trinity.”
 White, James R. The Forgotten Trinity. Minneapolis, MN. Baker Publishing Group. 1998. 89.