Scripture-first response
“Jesus did not know the hour.”
The Son’s human life includes genuine growth and limited human knowledge. The Spirit dwelling in Him remains the omniscient God.
What the objection is claiming
A limitation of the incarnate Son is treated as a limitation in God’s eternal knowledge.
Mark 13:32
But of that day and that hour knoweth no man, no, not the angels which are in heaven, neither the Son, but the Father.Open full referenceThe Son’s limited knowledge belongs to His authentic incarnate condition, not to a second deficient God-person.
How the passages answer it
Luke says Jesus increased in wisdom. Hebrews says He was made like His brethren. These are affirmations of real incarnation. The same Jesus contains all divine fullness bodily, so His human limitation is not evidence for a deficient second deity.