When God became man he took for himself “a human mind, subject to the same laws of perception, memory, logic and development as our own.” As the Son of God Christ knew all things, but as Son of Man he had to learn (Luke 2:52; Heb 5:8). Omniscient in his divinity; ignorant in his humanity.
This human ignorance is attested by Christ himself: “But of that day or hour no one knows, not even the angels in heaven, nor the Son, but the Father alone” (Mk 13:32). How omniscience and ignorance coexist in one person is a mystery beyond my comprehension. And yet the mystery may be a profound comfort. Like us, Jesus walked in darkness. Our Advocate knows firsthand the inner turmoil that accompanies our faith’s obedience as fear & ignorance whisper in our ear:
The other line of integration between the omniscience of the divine nature and the ignorance of the human is that just as Christ had to fulfill the office of Mediator within the limitations of a human body, so he had to fulfill it within the limitations of a human mind. Part of the truth here is suggested by the first of the three temptations in the desert: ‘tell these stones to become bread’ (Mt 4:3). The essence of the temptation was that the Lord disavow the conditions of the incarnation and draw on his omnipotence to alleviate the discomforts of his self-abasement. He could have turned the stones into bread; and he could (perhaps) have known the day and hour of his parousia. But the latter would have undone his work as surely as the former. Christ had to submit to knowing dependently and to knowing partially. He had to learn to obey without knowing all the facts and to believe without being in possession of full information. He had to forego the comfort which omniscience would sometimes have brought. This, surely, was a potent factor in the dereliction (Mk 15:34). The assurance of the Father’s love, the sense of his own sonship and the certainty of his victory were all eclipsed, and he had to complete his obedience as the one who walked in darkness, knowing only that he was sin and that he was banished to the outer darkness. He suffers as the one who does not have all the answers and who in his extremity has to ask, Why? The ignorance is not mere appearing. It is a reality. But it is a reality freely chosen, just as on the cross he chose not to summon twelve legions of angels. Omniscience was a luxury always within reach, but incompatible with his rules of engagement. He had to serve within the limitations of finitude.
-Donald Macleod, The Person of Christ, 169.