Mark 9:1 (NASB)
"And Jesus was saying to them, "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."
"Truly I say to you, this generation will not pass away until all things take place."
The word "Kingdom" in the New Testament often refers to the church. Colossians 1:13; Rev. 1:9; Matt. 16:18-19 demonstrates this:
"For He rescued us from the domain of darkness, and transferred us to the kingdom of His beloved Son"
"I, John, your brother and fellow partaker in the tribulation and kingdom and perseverance which are in Jesus, was on the island called Patmos because of the word of God and the testimony of Jesus."
18 "I also say to you that you are Peter, and upon this rock I will build My church; and the gates of Hades will not overpower it.
19 "I will give you the keys of the kingdom of heaven; and whatever you bind on earth shall have been bound in heaven, and whatever you loose on earth shall have been loosed in heaven."
And so "Kingdom" is a reference to the church in these passages, as it is in Mark 9:1.
Acts 1: 6- 9(NASB)
6 So when they had come together, they were asking Him, saying, "Lord, is it at this time You are restoring the kingdom to Israel?"
7 He said to them, "It is not for you to know times or epochs which the Father has fixed by His own authority;
8 but you will receive power when the Holy Spirit has come upon you; and you shall be My witnesses both in Jerusalem, and in all Judea and Samaria, and even to the remotest part of the earth."
9 And after He had said these things, He was lifted up while they were looking on, and a cloud received Him out of their sight.
When you combine the teaching of Mark 9:1 with Acts 1:8 here is what you get:
1) Jesus teaches that some of his disciples would not die until they saw the kingdom come with power.
2) They were to receive power when the Holy Spirit came upon them.
Do we find fulfillment in the New Testament of these promises to His disciples? The answer is yes.
1 When the day of Pentecost had come, they were all together in one place.
2 And suddenly there came from heaven a noise like a violent rushing wind, and it filled the whole house where they were sitting.
3 And there appeared to them tongues as of fire distributing themselves, and they rested on each one of them.
4 And they were all filled with the Holy Spirit and began to speak with other tongues, as the Spirit was giving them utterance.
This then is the "Kingdom" that Jesus has reference to in Mark 9:1. It is the church.
"praising God and having favor with all the people. And the Lord was adding to their number day by day those who were being saved."
So we do not look to some future fulfillment of the prophecy made in Mark 9:1. It was fulfilled in the first century, about 33 A.D. at the coming of the "kingdom" or church.
Now the context of Luke 21 is entirely different from that of Mark 9:1.
And here is an important point in Biblical interpretation. Words must be defined according to their context. "Kingdom" literally means, "God's rule." Most often it refers to the church in the New Testament, but it can also refer to the "Kingdom of Heaven," the eternal place of abode for the righteous which will come into existence at the end of time.
In Luke chapter 21 Jesus is discussing the need for man to be prepared for His second coming.
Verse 32 has caused much speculation and miss-application through the years … "Truly I say to you, this generation will not pass away until all things take place."
If the reference was to the "generation" of those who were living at the time of the Lord's words were spoken, then the entire discussion through verse 33 would have to be understood as being concerned with the destruction of Jerusalem and the collapse of the Jewish commonwealth. But if the "generation" had reference to the race of Israel, then the meaning would be that the Jewish people would survive until the Lord comes again.
I believe that it is proper to interpret the word "generation" to mean the Jewish family or race, in fact, I believe this is the way the word is translated in Luke 16:8.
This then is a prophecy that the Jewish people will be preserved until the coming of Christ. The marvelous and almost miraculous preservation of the racial individuality of the Jews, though dispersed among the nations, is the fulfillment of this prophecy.
So, Mark 9:1 & Luke 21:32 talk about two completely different things. One the coming of the church kingdom, the other the eternal kingdom at Christ's second coming.