Where is the Emphasis?

Luke 9:18-27 ESV
(18) Now it happened that as he was praying alone, the disciples were with him. And he asked them, "Who do the crowds say that I am?"
(19) And they answered, "John the Baptist. But others say, Elijah, and others, that one of the prophets of old has risen."
(20) Then he said to them, "But who do you say that I am?" And Peter answered, "The Christ of God."
(21) And he strictly charged and commanded them to tell this to no one,
(22) saying, "The Son of Man must suffer many things and be rejected by the elders and chief priests and scribes, and be killed, and on the third day be raised."
(23) And he said to all, "If anyone would come after me, let him deny himself and take up his cross daily and follow me.
(24) For whoever would save his life will lose it, but whoever loses his life for my sake will save it.
(25) For what does it profit a man if he gains the whole world and loses or forfeits himself?
(26) For whoever is ashamed of me and of my words, of him will the Son of Man be ashamed when he comes in his glory and the glory of the Father and of the holy angels.
(27) But I tell you truly, there are some standing here who will not taste death until they see the kingdom of God."

I want to make a doctrinal point today. Notice that this passage has a parallel in Matthew 16:13-20. The Roman Catholic Church takes the passage in Matthew to justify their belief in apostolic succession. In other words, Jesus made Peter the first pope and the rest have that authority as true apostles.

Why didn't Luke make a big deal about that? Here was a prime opportunity to reaffirm a key doctrinal point, right? Why didn't he emphasize it?

I think that arguing from silence is not particularly strong, but here the silence seems to shout.