Christ suffered, but it was not because he suffered that he became the Messiah. He is the Life-bearer/ grace-bearer for humanity and, of course, for the entire creation even before the incarnation. He poured out his life that we may have life. His suffering and self-emptying were life-giving.
Christ poured out his life as a ransom for many when Kings and priests gathered power and wealth. There is a king in the palace, there is a high priest in the temple. Our high priest is one among us being a source of life for us all.
Here, the question comes to the disciples: Can you drink the cup I have to drink? It is not simply about a readiness to suffer. It is about an attitude of becoming a ransom that offers life. One works, suffers, serves, and thus flowers, but we need to see what fruits are produced from these flowers. Are they life-giving fruits?
Life is non-sided, and the authority of life spans beyond boundaries. Disciples looked for power and position even in relation with Christ, because they understood him within the frames of powerful and wealthy priests and kings, not according to the nature of life.