Was Israel really supposed to be taken by surprise by the arrival of God Himself? What was the Messiah to be according to the expectations of the prophets of Israel? A man, God/man, higher order of angel? What were Peter and the rest of Israel looking for? History shows that a number of men had posed as the Savior of Israel and gained a following among the Jewish community. The nation correctly expected the liberator to come from the kingly line of David. They anticipated a man who would ascend the restored throne of David, vested with power to extend his rule to encompass all nations. This is what all the prophets had foreseen. Thus the last question the disciples asked Jesus before his final departure was, "Lord, is it at this time you are restoring the Kingdom to Israel?" They had every reason to believe that Jesus, as Messiah, would now bring about the promised restoration. Jesus' answer was merely, "It is not for you to know the times or the epochs which the Father has fixed by His own authority." Jesus did not question the fact that the Kingdom would one day be restored to Israel. The time of the great event was not to be revealed. That the Messiah would restore the Kingdom was the common thinking of Jesus and his disciples. It was, after all, what all the prophets had constantly predicted.
The disciples expected the Messiah to be born from the seed of David. As it would have appeared to any monotheistic Jew, the term Son of God carried the royal meaning it had acquired in the Old Testament. It designated a human being, a king especially related to God and invested with His spirit. That it implied the deity of Jesus in a Trinitarian sense would have been the most astounding, revolutionary information ever to invade the mind of Peter or any other religious Jew. Nowhere among the recorded words of the early Apostles, with the possible exception of Thomas, is there even the slightest indication that they were dealing with a God/man. Did Judas know he was betraying his creator and God? And on the occasions where the disciples deserted Jesus, were they aware they were leaving God? Did they believe God was washing their feet at the Last Supper? When Peter took out his sword to cut off a soldier's ear, did he think that the God who created him was somehow incapable of protecting Himself? At the Mount of Transfiguration, after the disciples saw a vision of Jesus in a future glorified state along with Moses and Elijah, they wanted to build three tabernacles, one for each of these three men. Why was no distinction made between these three, if one of them were God?
from pages 28- 29, The Doctrine of the Trinity