When Jesus began telling His disciples how He would suffer terrible things from the religious leaders of the day (death on a cross), He told them also in order to be His followers, they must be unselfish and carry their own cross.

Matthew 16:

21 From then on Jesus began to tell his disciples plainly that it was necessary for him to go to Jerusalem, and that he would suffer many terrible things at the hands of the elders, the leading priests, and the teachers of religious law. He would be killed, but on the third day he would be raised from the dead.

22 But Peter took him aside and began to reprimand him for saying such things. “Heaven forbid, Lord,” he said. “This will never happen to you!”

23 Jesus turned to Peter and said, “Get away from me, Satan! You are a dangerous trap to me. You are seeing things merely from a human point of view, not from God’s.”

24 Then Jesus said to his disciples, “If any of you wants to be my follower, you must give up your own way, take up your cross, and follow me. 25 If you try to hang on to your life, you will lose it. But if you give up your life for my sake, you will save it.