The disciples didn't desire to endure Christ's suffering...they lusted after his glory. But the truth they would later come to terms with is that they could not have one without the other.Read - Mark 10:35-45
Jesus, in a response to the pride of James and John's request, took a moment to help redirect his disciples towards a more accurate understanding of the purpose of his ministry on earth.
James and John (and the other disciples for that matter) were on Team Jesus! They saw what Jesus was accomplishing and how people were following him, and they were happy to be the first & favorite fans of this incredible and charismatic leader. However, what they didn't stop to see was that their new-found popularity and their relationship with Christ was appealing to the pride that was rooted in their hearts. They were famous for knowing Jesus, they had power because they were close to Jesus and they started to feel pretty good about themselves because of their association with Jesus.
The pride in their hearts was swelling up and eventually consumed them so much that they even became comfortable making openly selfish and self-centered requests of Jesus,
 "Grant us to sit one at your right hand and one at your left, in your glory".
So, Jesus' effort, in the verses that follow, was not to provide his disciples with a brief educational summation of Systematic Theology or a crash course on the subject of substitutionary atonement. Instead, Christ was making efforts to help his disciples to understand something quite different. Namely, their sin, their pride and their hearts selfish way of grabbing power and control. And, it was because of these very things that Jesus had to come to earth to surrender his life.
When Jesus said, "You do not know what you are asking. Are you able to drink the cup that I drink, or to be baptized with the baptism with which I have been baptized?" He was attempting to appeal to their hearts, to try and help them understand their own sin and pride.
Jesus later continued, "Whoever would be great among you must be your servant, and whoever would be first among you must be slave of all. For even the Son of Man came not to be served but to serve, and to give his life as a ransom for many."
Without question, Jesus saw the disconnect and he challenged his disciples to think about what they were REALLY asking of him. The disciples didn't desire to endure Christ's suffering...they lusted after his glory. But the truth they would later come to terms with is that they could not have one without the other.
Pride causes our hearts to see things through a distorted lens. Jesus’ disciples only saw one aspect of Christ’s ministry and in their selfishness; they lusted after the power and control they thought a close friendship with Christ would award them. Thankfully, by the work of the Holy Spirit, they were they able to eventually see what it was really going to cost them to obtain the glory which Christ purchased for them on the cross.
Far too often people choose Christ for their own convenience and gain, but this is not what a real and intimate relationship with Christ looks like. Jesus told his disciples in Mark 8:34-35
 “If anyone would come after me, let him deny himself and take up his cross and follow me.  For whoever would save his life will lose it, but whoever loses his life for my sake and the gospel's will save it."
Search your heart...test your motives for following Christ. If your desire is solely based on selfish gain, repent...God's mercy is everlasting...and he finds favor with those who humble themselves.
"For everyone who exalts himself will be humbled, and he who humbles himself will be exalted.” | Luke 14:11