"I believe; help my unbelief!" - Mark 9:24
Mark began the first half of his gospel with a prologue heralding "the way" (1:3) and brought it to a close with a question addressed to the disciples and the reader: "Do you not yet understand?" (8:21). He now opens the second half again "on the way" (8:27), with yet another query: "Who do you say that I am?" (8:29a). Upon our answer hangs the character of Christian witness in the world.
Do we really know who Jesus is and what he is about? In its long tradition of theological dogmatics, the church, like Peter, has answered assuredly: Jesus is the Christ (8:29b). It is something of a shock, then, to discover that in Mark's story this "correct" answer issues not in commendation (compare Matthew 16:17-19) but rather a confessional "crisis" (8:30-33). The crisis leads to Jesus' second call (see 1:16-20) to discipleship: the invitation to take up the cross (8:34f.).
This episode represents the midpoint of Mark's story; it is the narrative and ideological fulcrum upon which the gospel as a whole balances. Its point: If we wish to know and follow Jesus, theological orthodoxy is not sufficient. We must embrace Jesus' way.
And what is this way? The cross was in Mark's day 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. Thus discipleship is revealed as a vocation of nonviolent resistance to the powers.