Answer
Jesus’ lack of knowledge regarding the time of the second coming does not challenge the omniscience of God.
If there is a problem, it could be in our understanding.
Explanation
I keep out any of my philosophical inclinations. I leave all the theories and creeds behind. I focus on the Scripture.
When talking about Jesus, the Scripture states:
“having taken the form (morphe) of a servant” (Phlp 2:7; BibleHub).
History states that Jesus was 100% a human being. Hardly people deny this. So, this much is sure.
Thus, morphe of a servant means a human being.
But there is more in the above statement. He actively “took” the form of a human being.
No human has ever taken a form of something at his volition before birth. We are all simply born as human beings unaware of any wishes or ambitions on our part before birth.
Only a Person who existed before can “take” a form He wants!
Do we have any such information like that?
Yes, here it is:
“Christ Jesus who existing in the form (morphe) of God” (Phlp 2:6;
BibleHub).
Scripture reveals that Jesus Christ was pre-existing before His incarnation as God.
If morphe of servant is 100% human being, then morphe of God is 100% God. This is an undeniable logical conclusion.
Morphe cannot mean two different things in the same place!
Other Scripture verses prove the same thing:
“The Word was God” (John 1:1)
“And Thomas answered and said to Him, My Lord and my God!” (John
20:28).
So, things are clear to me now. Jesus as the Word existed before His incarnation as God Himself but later, as the Almighty God He took upon Himself the low form of a physical human being.
But what happened in between?
“not considered the to-be-equal-with-God something to be grasped
(something to be held on) but EMPTIED Himself” (Phlp 2:6-7;
BibleHub).
Who can “empty” himself?
Can a human being empty himself? No.
Can a mighty lion empty itself? No.
Can a tiny ant empty itself? No.
Only an Almighty God can empty Himself! And that is exactly what the Almighty God did and He became a human being!
What did He empty Himself of?
“Empty” is “κενόω” (kenoō) in Greek. BibleHub gives the following explanation under the heading “Usage”:
“The verb κενόω primarily means "to empty" or "to make void." In the
New Testament, it is often used metaphorically to describe the act of
making something of no effect or rendering it powerless. It can also
imply the act of divesting oneself of status or privilege.”
(https://biblehub.com/greek/2758.htm)
The same Greek word is used in these verses: “void” (Rom 4:14), “made of none effect” (1 Cor 1:17), “void” (1 Cor 9:15), and “in vain” (2 Cor 9:3).
The word clearly shows that God forsook all the glory, power, status and privileges of Godhead.
The same word does not refer to any “concealment” or “putting on something above an existing something”, “union of 2 things” etc. It simply means “putting off what was before”.
So, when Jesus Christ walked on the earth as a man, He was 100% a human being without any attributes of a powerful God. He hungered, felt thirsty and got tired. Anybody could hurt Him (in fact they killed Him). He prayed to His Father God.
Please don’t misunderstand: He is the same Person who was God. So, in that sense, Jesus is God but without the glory and power of Godhead.
Scripture confirms:
“Jesus Christ, the same (Person) yesterday and today and forever” (Heb
13:8).
As a 100% human, Jesus said:
“I am able to do nothing from Myself; just as I hear, I judge; and
My judgment is just, for I do not seek My will, but the will of the
One sending Me, the Father” (John 5:30).
As a 100% human without Godly power, Jesus said:
“But concerning that day and the hour, no one knows, not the angels,
those in Heaven, nor the Son, except the Father” (Mar 13:32).
So how did Jesus do the mighty things?
Jesus Himself answers:
“And Jesus lifted His eyes upward and said, Father, I thank You that
You heard Me. And I know that You always hear Me” (John 11:41-42).
“…I cast out the demons by the Spirit of God…” (Mat 12:28).
So, Jesus was able to do many mighty miraculous acts through the help of God the Father.
Yes, Jesus did everything through His Father who was ever ready to hear and help His Son.
Does Jesus know the day and hour now?
Yes, He knows. After His resurrection, He declared:
“All authority in Heaven and on earth was given to Me” (Mat
28:18).
A Person who has started wielding ALL authority in Heaven and on earth (as before the incarnation) will definitely know the day and hour of His second coming.
“Because you kept the Word of My patience, I also will keep you out of
the hour of trial which is going to come on all the habitable world in order to try those dwelling on the earth” (Rev 3:10).
This is talking about the Great Tribulation that is to come at the end of the world. How can Jesus protect His followers if He doesn’t know when that “hour” is coming?
So, He knows now!
Conclusion
“with God all things are possible” (Mat 19:26).
Problem is with the limitations of human understanding.