Jesus was talking to His disciples when He said (in Matthew 16:28, ESV), "Truly, I say to you, there are some standing here who will not taste death until they see the Son of Man coming in his kingdom
That literally took place on several occasions following His statement: (1) when Jesus stood in His glory on the mountain - before Peter, James and John, (2) after His resurrection - to numerous disciples, (3) when Jesus was taken up into Heaven, and finally, (4) to the Apostle John when Jesus appeared to him on the island of Patmos.
However, I believe Jesus' prophetic statement applies to more than the people who were physically standing with Him before His death. (See Escher and Prophecy Fulfillment to read the basic premise.) The statement seems likely to be appropriate for other generations.
Jesus' words reverberate down the strand of time as His kingdom becomes more visible.
» The apostle Paul identifies one generation in 1Corinthians 15:23 when he talks about Jesus returning to raise the dead in Christ and to change His followers who still live.
» Jesus speaks of an occasion when everyone alive will see Him in Matthew chapter 24. There, He and His disciples discuss the signs of the end of the age. Jesus tells them that His coming will be not in secret, but similar to a lightning strike where all can see it.
» Philippians 2:9-11 (ESV) tells us of a powerful event fulfilling His statement: "Therefore God has highly exalted him and bestowed on him the name that is above every name, so that at the name of Jesus every knee should bow, in heaven and on earth and under the earth, and every tongue confess that Jesus Christ is Lord, to the glory of God the Father." In a future age, even the mention of His Name provides evidence that He has come into His kingdom.
As Christians living in a fallen world, we long to see Jesus honored in every way. Now, we see His kingdom come one lost sinner at a time as they find new life in Him. Nevertheless, a day is coming when "some standing here will not taste death until they see the Son of Man coming in his kingdom." Jesus says in Revelations 22:20, "Surely I am coming soon."
So be it. Come, Lord Jesus.