It is accepted that Jesus took on human nature in its full sense, as we are. For this reason Scripture says:
“For this reason he had to be made like them, fully human in every way, in order that he might become a merciful and faithful high priest in service to God, and that he might make atonement for the sins of the people.”
Jesus’s human nature was subjected to the same limitations and faculties common to all humans; subjected to tiredness (Jn 4:6-7), hunger (Mk 11:12), physical sensitivity (Mt 27:34), need of sleep (Mk 4:38), circumscription of space (Jn 11:21) and also passions, including love (Mk 10:21), anger (Jn 2:14-16), sadness (Jn 11:33-36) and fear (Lk 22:42-44). He also possessed qualities like capacity to grow, intelligence and capability to learn (Lk 2:52). In this respect, his human nature could be identified truly as one of us.
Jesus was a real human being.
However, in order to represent all of humanity, Jesus had to incarnate like Adam as head of humanity, the way he was prior to the fall. The atoning sacrifice would not be efficient is the offering was imperfect or sinful (Ex 12:5; Lv 1:2-4). Since the object of the atonement is repayment and ransom, a valuable offering had to be given to cover the debt. A sinful, imperfect, fallen human nature could not cover that deficit because it would be deficient and of no value itself. And part of that deficient human nature was physical mortality, which came as a consequence of sin (Gn 2:17; 3:19; Ro 6:23).
Lord Jesus became human in the pristine condition Adam was made prior to the Fall, including physical immortality, and offered this perfect human nature in place of the imperfect human nature of the rest of us to repay our sin.
Jesus lived an immortal human life, not subjected to aging or sickness or concupiscence. When Lord Jesus died, he surrendered his physical life to the wounds of the Cross, and expired not before, not after the mission was completed, when and how he wanted it, as not by the natural effect of his execution. (Jn 5:26; 10:17-18; 19:30)
“No one takes it from me, but i lay it down of my own accord. i have authority to lay it down and authority to take it up again.”