Matthew 20:17-28
The theme of this Gospel Reading is Servant Leadership, which we can amply see in Jesus. One of the hallmarks of Servant Leadership is Humility. And this we see in how Jesus is obedient to the will of God Father, i.e. to go to Jerusalem knowing ridicule, pain and death await him there. He has known since his meeting with Moses and Elijah at his Transfiguration, what awaits him in Jerusalem, and yet in all humility he goes towards the Cup, which awaits him. So it is with us, without crossing the sea of suffering and being baptised into it, we shall not receive our crown. This is what is highlighted in the second part of the Gospel.
The mother of James and John, like all mothers want the best for her children, and so requests it for them. Even James and John want it. Yet Jesus in perfect communion with the Father, knows that it is but right for the Father to bestow these positions on the right and left to whom he sees right, and so Jesus defers the right to choose. The better part in the dialogue is that James and John do not distance themselves from the violence that awaits them, (though without knowing the nature of the violence), and even Jesus affirms them by saying that they will be joined with him in and through the suffering that awaits them.
Suffering is like polish paper/sandpaper, it does hurt, but it also perfects.