In Isaiah 53:10, God's promises concerning the suffering servant are conditional: "If he would . . . he shall see. . . ." Does this apply to Jesus?
According to the New Testament, Jesus had specific knowledge of his mission on earth and his destiny in heaven. For example, in the Gospel of John, Jesus says, "I . . . came down from heaven" (John 6:51) and "I know where I came from, and where I am going" (John 8:14); in the Gospel of Matthew he told his disciples that he "must go to Jerusalem and suffer many things . . . and be killed . . . and be raised up on the third day" (Matthew 16:21). What he supposedly left temporarily in heaven and his alleged additional rewards on his heavenly return are found in Philippians 2:6-11).
There should be no need for God to promise a reward on condition that Jesus fulfill His wishes ("If he would"). If Jesus is all that Christianity claims he is, then God knew that this incarnate sinless divine being would fulfill all that was required of him. It certainly makes no sense to think God would promise to reward such a heaven bound eternal being with having children and prolongation of days. Such things are promised to humans not to one who is supposedly eternal.
According to New Testament doctrine, the sinless incarnate divinity, Jesus, could not fail or refuse to carry out God's plans for mankind. Thus, there was no doubt that Jesus would carry out God's plan and would be uniquely rewarded for his effort (Philippians 2:9). As a result, the application to the New Testament's Jesus of the conditional, "If he would . . . he shall see," that speaks in profoundly human terms makes no sense.
Once again, we see that Isaiah 53 does not refer to Jesus.