28 You have heard Me say to you, ‘I am going away and coming back to you.’ If you loved Me, you would rejoice because I said, ‘I am going to the Father,’ for My Father is greater than I.
for [because] My Father is greater than I.
The “greater” here is a contrast between the Father in His glory and the Son in His incarnation. The situation would be better for Jesus since He was leaving His incarnate body and going back to the Father. The emphasis in this passage is not on the essential being of the Son but on the return from a finite to an infinite existence.
The reason the apostles should have been glad that Jesus was returning to His Father is that He would return to His former glory that He had with the Father before becoming incarnate. That was His gain and their loss. Their grief over His departure was selfish.
In addition to the differences between the Father and Son in His humanity, theologically there is a distinction in their roles. The idea of the Father being “greater” than Jesus has to do with roles within the Trinity. The Father plans, the Son executes the plan, and the Holy Spirit brings the plan to individuals. Role has nothing to do with essence. The Father and Son are one in essence (everywhere present, all knowing, etc.).
The Father and Son are one in essence but distinct in role.
Arians, Gnostics, Unitarians, and Jehovah Witnesses claim that Jesus is a lesser god, making Him a created being or merely “a god.” Making Jesus a lesser god is polytheism. Not only was He not created (as some claim), but He was Himself the creator of the universe (Jn 1:3). The Father and Son are co-equal and co-eternal. Jewish monotheism rejected polytheism. They would have forbidden the idea that Jesus was “a god.”
The distance of essence between the human being and God is so great that it is incalculable. There is no categorical comparison between God and the human being. Jesus spoke from His humanity, not His deity, when He said, “The Father is greater than I.” The Father retained His glory, while the Son set aside the voluntary use of His eternal attributes to step into a human body (Php 2:6-8). Jesus would return to the full use of His pre-existing glory at His ascension (Jn 17:5).
The issue in our passage is not Christ’s nature or essential being but His role. We see both Christ’s essential being as God and His humanity in a passage like Philippians 2:5-8. He was equal with the Father in His essence, but He set aside the voluntary use of His incommunicable attributes (while at the same time retaining them in undiminished form in His deity) to take on a human body. He assumed the role of a Mediator. In the latter sense He was subject to the Father.
The President of the U.S. and the Prime Minister of Canada are both greater than I am as a person. That simply means they hold greater rank than I do; it does not mean that either is more of a human being than I am. The Father has rank over the Son, but that does not mean that the Son is of lesser essence than the Father. They both are all knowing and all powerful in their essence, but they have different roles.
The surrounding context clarifies what type of greatness is in view. Jesus was going back to the Father, who had commissioned His mediatorial ministry on earth (Jn 13:16). If the apostles truly loved Him, they would have been glad for His return to the Father.
Christians are often found to have more concern over their own problems than what brings our Lord joy. If the apostles had loved Jesus in the way that they should have, they would have been glad for His return to the full use of His attributes as God. They would have wanted the best for Him.
Thus, the proper context of “My Father is greater than I” is that Jesus is obedient to and dependent upon the Father (Jn 4:34; 5:19–30; 8:29; 12:48–49) and that the Son assumes the role of the Father’s Mediator in creation, revelation, and redemption.