Hebrews 12:2

"looking unto Jesus, the author and finisher of our faith, who for the joy that was set before Him endured the cross, despising the shame, and has sat down at the right hand of the throne of God." (Heb 12:2)

What a great price that Jesus has paid for us, but now He sits at the right hand of God. This reminds me of an incident in the gospels. In Mark 10:35-45 it quotes:

35 Then James and John, the sons of Zebedee, came to Him, saying, "Teacher, we want You to do for us whatever we ask."
36And He said to them, "What do you want Me to do for you?"
37They said to Him, "Grant us that we may sit, one on Your right hand and the other on Your left, in Your glory."
38But Jesus said to them, "You do not know what you ask. Are you able to drink the cup that I drink, and be baptized with the baptism that I am baptized with?"
39They said to Him, "We are able."
So Jesus said to them, "You will indeed drink the cup that I drink, and with the baptism I am baptized with you will be baptized; 40but to sit on My right hand and on My left is not Mine to give, but it is for those for whom it is prepared."
41And when the ten heard it, they began to be greatly displeased with James and John. 42But Jesus called them to Himself and said to them, "You know that those who are considered rulers over the Gentiles lord it over them, and their great ones exercise authority over them. 43Yet it shall not be so among you; but whoever desires to become great among you shall be your servant. 44And whoever of you desires to be first shall be slave of all. 45For even the Son of Man did not come to be served, but to serve, and to give His life a ransom for many."

When James and John asked to sit on the right and left of Jesus, Jesus told them that they must be able to drink the cup that He drinks. Of course they had no clue what that cup is until later. The cup that Jesus drank was a bitter cup, it was the cup of sacrifice and of suffering. Jesus suffered for us because he came 'to serve, and to give His life a ransome for many.'

During the apostolic times, both brothers suffered for the gospel. They kept their promise to drink the bitter cup. James later beacme the first martyr. Even though James and John appeared to upheld themselves with such a request, they were able to bear the consequences and carry out their promise. Therefore, to be great in the kingdom of heaven means that we must be able to bear the same cross that Christ bore for us. We must be able to drink that bitter cup, to suffer for the gospel and for Christ. We must realize that the greater our work in church is, the more we are expected to serve others.

Hence, it isn't terrible to desire greatness in heaven as long as we live out to the expectations of God on earth. Contrarily, I believe God hopes for each one of us to pursue that greatness. However, that means we must sacrifice and humble ourselves throughout our transient life on earth as the apostles did.