In Matthew 16:28, Christ indicates that some of the disciples will see Him coming in His kingdom. This is taken by Preterists as an indication that Christ will return in their lifetimes. However, it seems clear instead that this is a reference to the Mount of Transfiguration scene to follow. There are numerous reasons for understanding it this way.
1. The parallels indicate that this is a reference to God beginning to give the kingdom over to Christ.
And he said to them, “I tell you the truth, there are some standing here who will not experience death before they see the kingdom of God come with power.” (Mark 9:1)
But I tell you most certainly, there are some standing here who will not experience death before they see the kingdom of God.” (Luke 9:27)
I tell you the truth, there are some standing here who will not experience death before they see the Son of Man coming in his kingdom." (Matt 16:28)
The Son of Man coming in His kingdom is a parallel idea to the kingdom of God coming with power and the kingdom of God itself. We are told that the kingdom of God has already come. We are also told that the kingdom of God comes with power in Jesus' ministry. It also comes with power in the ministry of the apostles and the church in the coming of the Holy Spirit. But the point I would make here is that I think that Preterists miss the complexity of this verse by assuming that there is only one coming of Christ, only one reception of His kingdom, rather than many, as the New Testament indicates. They do not understand the micro-macro nature of apocalyptic speech, the already-not yet nature of a future fulfillment also being fulfilled in smaller ways before the time, and hence, they conclude by the language preceding Christ's statement here that this must refer only to the Second Advent, and not anything that might come before and would be spoken of as one with it, even though separated by time.
2. The placement of the narrative.
But there is more to indicate that the fulfillment, at least the initial fulfillment of Christ's coming/reception of His kingdom is on the Mount of Transfiguration.
First, it is important to note that every single Synoptic places the Mount of Transfiguration scene immediately after Christ's statement here. This is significant, since the Gospel authors seem to have no problem moving things around in order to present their Gospels around their themes. Yet, even with differing themes and the recasting of many events, this one is placed immediately after what Christ says here in every one of them.
Narrative makes it arguments this way. When an author places things together in a narrative he is often meaning to communicate that the one goes with the other.
3. The mimicking of language from the Daniel 7 "Son of Man coming in the Clouds" narrative in the Mount of Transfiguration Scene.
But there is more to consider even than this. The language of coming, as we have seen in the other Gospel presentations of what Christ said, is actually the language of the Son receiving the kingdom. It is a royal conferment, the transference of majesty from the Father to the Son. This idea is taken from Daniel 7.
In Daniel 7, the Son of Man comes on the clouds of heaven and goes up the Ancient of Days, i.e., the Father, and receives the kingdom from Him. God is described as glowingly white like snow, like wool, and glowing like fire.
In the Mount of Transfiguration scene, Jesus is the one glowing, a display of His deity, but he ascends/goes up to the Father on the mountain, they are enveloped in a cloud, and the Father confirms the authority/power the Son has and that all should now listen to Him. Even the declaration by the Father, i.e., the Ancient of Days, that Jesus is His one beloved Son, is terminology of kingship, as the anointed king was considered God's son.
The coming language of Matthew 16:28 is explained as reception of the kingdom/conferment of the kingdom by the Father to the Son. It is a fulfillment of Daniel 7 (not the fulfillment, but a fulfillment), where God gives His majesty to the Son in the clouds of the sky, here upon the mountain top.
So the Mount of Transfiguration is a beginning fulfillment that is witnessed by a few of the disciples a few days after Christ proclaims that some will not taste death until they have seen the kingdom of God//the kingdom come with power//the Son coming in/into His kingdom.
4. Peter links them together.
But there is even more than this that indicates that the Mount of Transfiguration fulfills this prediction, at least in part. Peter links the two ideas together himself.
In 2 Peter 1:16-18, Peter states the following:
For we did not follow cleverly concocted fables when we made known to you the power and parousia "coming" of our Lord Jesus Christ; no, we were eyewitnesses of His majesty (i.e., royal conferment). For He received honor and glory from God the Father, when that voice was conferred to Him by the Majestic Glory: “This is my dear Son, in whom I am delighted.” When this voice was conveyed from heaven, we ourselves heard it, for we were with him on the holy mountain.
Notice, both the ideas that power and royalty were given to Christ on the Mount of Transfiguration, and this is referred to as Christ's parousia "coming."
The disciples will also witness Christ's reception in His resurrection, His ascension, the coming of the Holy Spirit at Pentacost, etc. Some will see it in His destruction of the temple in A.D. 70 as well. There are many "receptions/comings" of His kingdom that will lead up to the final and ultimate coming and reception of His total kingdom in the end. Indeed, as we have noted, He states to the priests before His death that "from now on, you will see the Son of Man sitting at the right hand of Power and coming in the clouds of heaven" (Matt 26:64), which indicates an ongoing reception of the kingdom (note the contradiction between sitting at God's right hand and coming in the clouds if taken literally, yet both convey the reception of power in the Bible).
Luke even records that the ultimate day, the final coming, will not be seen by the disciples even though they will see other days, other comings, that precede it. In Luke 17:21, Christ argues that the disciples already have seen the coming of the kingdom, but in v. 22, that they have not yet, nor will they, see the final coming of Christ in their lifetimes.
Hence, the most natural understanding of Christ's words is to see them in light of the Mount of Transfiguration first. If there are other fulfillments the disciples will see, and there are, then they are secondary to the fact that Christ's prediction is already fulfilled a few days later.