What is the “power” in the kingdom of God?
Jesu promises some of his apostles,that they would not taste death until they see the kingdom.
In Mark 9:1 Jesus says:
Truly I say to you, there are some of those who are standing here who
will not taste death until they see the kingdom of God after it has
come with power. (NASB).
This promise was fulfilled "six days later" (or “eight” according to Luke, who apparently includes the day of the promise and that of the fulfillment) when Peter, James, and John accompanied Jesus on a " high mountain"
Mark 9:2 (NASB)
2 Six days later, Jesus *took with Him Peter and [a]James and John,
and *brought them up on a high mountain by themselves. And He was
transfigured before them;
Luke 9:28-36 (NASB)
28 Some eight days after these sayings, He took along Peter and John
and James, and went up on the mountain to pray. 29 And while He was
praying, the appearance of His face became different, and His clothing
became white and gleaming. 30 And behold, two men were talking with
Him; and they were Moses and Elijah, 31 who, appearing in glory, were
speaking of His departure which He was about to accomplish at
Jerusalem. 32 Now Peter and his companions had been overcome with
sleep; but when they were fully awake, they saw His glory and the two
men standing with Him.
33 And as these were leaving Him, Peter said to Jesus, “Master, it is
good for us to be here; let us make three [d]tabernacles: one for You,
and one for Moses, and one for Elijah”—not realizing what he was
saying. 34 While he was saying this, a cloud formed and began to
overshadow them; and they were afraid as they entered the cloud. 35
Then a voice came out of the cloud, saying, “This is My Son, My Chosen
One; listen to Him!” 36 And when the voice had spoken, Jesus was found
alone. And they kept silent, and reported to no one in those days any
of the things which they had seen.