For the Son of Man will come in the glory of His Father with His angels, and then He will reward each according to his works. Assuredly, I say to you, there are some standing here who shall not taste death till they see the Son of Man coming in His kingdom. This verse informs us of our soul. Lets summarize what Jesus has taught, 1. The first lesson is that Jesus is speaking to disciples.
Disciples are people who are saved.
Therefore He is talking to believers, not to unbelievers. He is speaking to believers. Let him deny himself This means disregarding your privileges. It means setting aside your own thoughts, will, and emotions and to choose to take on His. This is much deeper than to deny yourself.