1. Why did Jesus die on the cross?
2. What or who needed Jesus to die on the cross?
3. Did Jesus have to die on the cross for humanity and to save humanity?
4. Does the cross save and if so how?
These four questions are all the same. The why and how are not different. Of course, the "how" can be taken in many ways. In our case, we know of no "mechanism" by which salvation was applied to humanity through the cross. The term "world" is essential to define. "World" in this case is similar to "worldly" or "secular." it refers to the power structure that exists everywhere: the power of money, access to power and the ruthlessness it takes to get both. It is not the world in the sense of Creation. Without knowing this definition, nothing here (or anywhere) on this topic will make sense.
"Come out from your country and your people, and come unto the land that I shall show you" (Gen. 12:1). This saying contains within it the mystery of the Cross because it corresponds exactly with Paul who, boasting in the Cross, says, "the world has been crucified to me" (Gal. 6:14). In truth, for him who left his country never to return, his homeland and world according to the flesh has been put to death and destroyed, and this is the Cross (Gregory Palamas, Homily 11, 92).
This is the first issue. The cross is ritual death. In the ancient world, to remove oneself from the traditional ties of the community meant death in a real sense. Yet, those who died while still being a member were a part of it. Death was not merely the cessation of breathing, but severing of ties that make life possible. Hence, this first reason is to say that the Cross was graphic proof of the fact that true followers of Christ will be hated. They will be "dead" in the sense that they lose all ties with the mundane world.
Freedom from corruption, in any event, would have been joined to freedom from the passions; and in the presence of passionlessness, sin would have no place. But since they did sin, they were surrendered to corruption. Having become corrupt, they begat offspring like unto themselves. But desires, fears and pleasures accompany them who are in this likeness. Reason wars against these passions, and winning, is proclaimed victorious, but suffering defeat, it is put to shame (St. John Chrysostom, Commentary on Psalm 50).
This is not that different from Palamas above. St. John here is holding that the cross shows an image of a total lack of ...
Jesus and the cross is examined. The expert determines if Jesus died on the cross for humanity and to save humanity.