in Mark 8:28-38, Jesus is speaking to his disciples
And Jesus went out, and his disciples, into the towns of Caesarea Philippi: and by the way he asked his disciples, saying unto them, Whom do men say that I am? ...
immediately following in Mark 9:1 Jesus says
And he said unto them, Verily I say unto you, That there be some of them that stand here, which shall not taste of death, till they have seen the kingdom of God come with power.
which is followed in Mark 9:2-8 where Peter, and James, and John see Jesus transfigured before them and a cloud that overshadowed them, and a voice coming out of a cloud, saying, this is my beloved Son: hear him.
That there be some of them that stand here, which shall not taste of death, till they have seen the kingdom of God come with power.
Acts 1:8
8 But ye shall receive power, after that the Holy Ghost is come upon you: and ye shall be witnesses unto me both in Jerusalem, and in all Judaea, and in Samaria, and unto the uttermost part of the earth.
The power came on the day of Pentecost was something no one since the time of Moses had ever seen.
The kingdom of God came with power.