Scripture-first response
“The Father is greater than Jesus.”
The Father is greater than the Son’s servant position and human condition. The same discourse says seeing Jesus reveals the Father because the Father dwells in Him.
What the objection is claiming
Jesus’ humbled incarnate position is treated as proof of lesser divine nature.
John 14:28
Ye have heard how I said unto you, I go away, and come again unto you. If ye loved me, ye would rejoice, because I said, I go unto the Father: for my Father is greater than I.Open full referenceThe Father is greater than the Son with respect to the Son’s humbled incarnate position and mission.
How the passages answer it
Philippians 2 describes voluntary humiliation from God’s form into servant form. John 14 holds together the humbled Son and the indwelling Father. The comparison concerns position and mission in the incarnation, not competing degrees of deity.