NOTES for Mat 16:13-28
The apostles do not understand Jesus at once. Peter, calling Him Christ, that is, the Anointed One, King of Israel, cannot take in His predictions of His own death in Jerusalem.
Do we understand what it means to be Christians? For us, Christianity is most often associated with a certain form of spiritual life, a particular worldview, particular behavior, particular rules of life. Does our "salvation of the soul" not contrast with the words about those who "want to save their soul (life)"? He does not speak about rules, about a worldview, about "Christian values." He speaks about the cross, about bearing the cross, as the mark of a Christian.
If this is hard for us to understand and take in, we should not despair; the apostles could not either. The only important thing is to move along the path of this awareness. And in order to move, we need to know the goal.