In the gospel of Mark, Jesus speaks of the cross and ties it to the meaning of discipleship: "If any want to be my followers, let them deny themselves and take up their cross and follow me" (Mark 8:34).
Think for a moment what the cross meant for those who were listening to Jesus and for those who were reading Mark's gospel some 30 years later. Ched Myers puts it this way: "The cross in Mark's day was neither religious icon nor metaphor for personal anguish or humility. It had only one meaning: that terrible form of capital punishment reserved by imperial Rome for political dissenters." Myers goes on: "The cross was a common sight in the revolutionary Palestine of Mark's time; in this recruiting call, the disciple is invited to reckon with the consequences facing those who dare to challenge the hegemony of imperial Rome."
With this ominous invitation, the cost of discipleship got much, much bigger. Embracing Jesus means embracing that cross. Mark doesn't say it, but I suspect that after these words, the crowds around Jesus got smaller.
Paul takes up the theme of the cross in his first letter to the church at Corinth: "For the message about the cross is foolishness to those who are perishing, but to us who are being saved it is the power of God" (1 Corinthians 1:18). Taking up the cross and following Jesus not only entails great cost, it is also viewed by the world as an utterly foolish thing to do.