Hello PW. Below is Luke's version:
The Prophecy:
"Truly I tell you, some who are standing here will not taste death before they see the kingdom of God.”
Prophecy fulfilled:
About eight days after Jesus said this, he took Peter, John and James with him and went up onto a mountain to pray. As he was praying, the appearance of his face changed, and his clothes became as bright as a flash of lightning.
Right after Jesus makes the prophecy, the next verse says, "about eight days after Jesus said this" which lets the reader know that the following information is related to the previous prophecy. Those who were standing there was Peter, James and John. They would not taste of death because eight days later Jesus took them up a high mountain where they saw the Lord in His glorified state, which is what he was referring to when he said "they would see the kingdom of God." It is not referring to the end of the age.
You and others attempt to use this scripture as proof that Jesus returned to the earth while Peter, James and John were still alive, but that is not what the Lord was referring to. It was his transformation into His glorified state that he was referring to.
Each of the three gospels lists it in the following way:
Matt.16:28 - Truly I tell you, some who are standing here will not taste death before they see the Son of Man coming in his kingdom
Mark 9:1 - Truly I tell you, some who are standing here will not taste death before they see that the kingdom of God has come with power.”
Luke 9:27 - Truly I tell you, some who are standing here will not taste death before they see the kingdom of God
In reference to Peter, James and John seeing "the kingdom of God," it was referring to Jesus' presence demonstrating the power of God. Below is another example that Jesus' reference to "the kingdom of God" was not referring to His return to end the age:
"And if I drive out demons by Beelzebul, by whom do your people drive them out? So then, they will be your judges. But if it is by the Spirit of God that I drive out demons, then the kingdom of God has come upon you.
In the scripture above, the act of Jesus casting out demons by the Spirit of God was referred to as the kingdom of God having come upon them and not in reference to Jesus return to the earth to end the age. Peter, James and John seeing Jesus in His glorified state is what Jesus was referring to regarding them seeing the kingdom of God having come with power.
It was their seeing the Lord in His glorified state that He was referring to and was fulfilled eight days after the Lord told them.