Q: The Jehovah Witnesses just stopped by and refered to John 14:28b (“my Father is greater than I”) and said that Jesus is less than the Father, so how can he be God? In what way can I resolve this apparent difficulty.
A: First of all, Scripture expressly says that the Son is equal to the Father. In Philippians Paul speaks of how the Son voluntarily took on a humble human form even though he was equal with the Father:
“Christ Jesus, who, though he was in the form of God, did not count equality with God a thing to be grasped, but emptied himself, taking the form of a servant, being born in the likeness of men” (Philippians 2:6b-7).
John’s gospel itself–the very one which the Witnesses quoted–also stresses the equality of the Son with the Father:
“[T]he Jews sought all the more to kill him, because he not only broke the sabbath but also called God his Father, making himself equal with God” (John 5:18).
Given these explicit declarations of the Son’s equality with the Father, we must explain statements like “my Father is greater than I” in some other way, as referring to some other kind of difference between the two Persons than a difference of essence.
And there is no difficulty in doing this, for the Father is above the Son in the economy of the Trinity and in the order of Persons (the Son is begotten by the Father), but not they are equal in essence. In fact, they are equal in essence precisely because the Jesus is the Son of the Father.
If I, as a man, fathered a son, my son would have the same essence I do–being a man–and while I might be greater than him in rank or position (by virtue of being his father), we would have equal essences.
This is the situation between the Son and the Father. Both have the same essence, and so both are equal in what they are, even if the Father is above the Son in other senses.