Matthew 16:27
For the Son of man shall come in the glory of his Father—This seems to refer to Daniel 7:13, 14. "Behold, one like the Son of man came—to the ancient of Days—and there was given him dominion, and glory, and a kingdom, that all people, and nations, and languages should serve him." This was the glorious Mediatorial kingdom which Jesus Christ was now about to set up, by the destruction of the Jewish nation and polity, and the diffusion of his Gospel through the whole world. If the words be taken in this sense, the angels or messengers may signify the apostles and their successors in the sacred ministry, preaching the Gospel in the power of the Holy Ghost. It is very likely that the words do not apply to the final judgment, to which they are generally referred; but to the wonderful display of God’s grace and power after the day of pentecost.
Matthew 16:28
There be some—which shall not taste of death—This verse seems to confirm the above explanation, as our Lord evidently speaks of the establishment of the Christian Church after the day of pentecost, and its final triumph after the destruction of the Jewish polity; as if he had said, "Some of you, my disciples, shall continue to live until these things take place." The destruction of Jerusalem, and the Jewish economy, which our Lord here predicts, took place about forty-three years after this: and some of the persons now with him doubtless survived that period, and witnessed the extension of the Messiah’s kingdom; and our Lord told them these things before, that when they came to pass they might be confirmed in the faith, and expect an exact fulfillment of all the other promises and prophecies which concerned the extension and support of the kingdom of Christ.
To his kingdom, or in his kingdom. Instead of βασιλεια, kingdom, four MSS., later Syriac, Coptic, Ethiopic, Saxon, and one copy of the Itala, with several of the primitive fathers, read δοξη, glory: and to this is added, του πατρος αυτου, of his Father, by three MSS. and the versions mentioned before. This makes the passage a little more conformable to the passage already quoted from Daniel; and it must appear, very clearly, that the whole passage speaks not of a future judgment, but of the destruction of the Jewish polity, and the glorious spread of Christianity in the earth, by the preaching of Christ crucified by the apostles and their immediate successors in the Christian Church.
1. THE disciples, by being constantly with their Master, were not only guarded against error, but were taught the whole truth: we should neglect no opportunity of waiting upon God; while Jesus continues to teach, our ear and heart should be open to receive his instructions. That what we have already received may be effectual, we must continue to hear and pray on. Let us beware of the error of the Pharisees! They minded only external performances, and those things by which they might acquire esteem and reputation among men; thus, humility and love, the very soul of religion, were neglected by them: they had their reward—the approbation of those who were as destitute of vital religion as themselves. Let us beware also of the error of the Sadducees, who, believing no other felicity but what depended on the good things of this world, became the flatterers and slaves of those who could bestow them, and so, like the Pharisees, had their portion only in this life. All false religions and false principles conduct to the same end, however contrary they appear to each other. No two sects could be more opposed to each other than the Sadducees and Pharisees, yet their doctrines lead to the same end—they are both wedded to this world, and separated from God in the next.
2. From the circumstance mentioned in the conclusion of this chapter, we may easily see the nature of the kingdom and reign of Christ: it is truly spiritual and Divine; having for its object the present holiness and future happiness of mankind. Worldly pomp, as well as worldly maxims, were to be excluded from it. Christianity forbids all worldly expectations, and promises blessedness to those alone who bear the cross, leading a life of mortification and self-denial. Jesus Christ has left us an example that we should follow his steps. How did he live?—What views did he entertain?—In what light did he view worldly pomp and splendor? These are questions which the most superficial reader may, without difficulty, answer to his immediate conviction. And has not Christ said that the disciple is not ABOVE the Master? If HE humbled himself, how can he look upon those who, professing faith in his name, are conformed to the world and mind earthly things? These disciples affect to be above their Lord; and as they neither bear his cross, nor follow him in the regeneration, they must look for another heaven than that in which he sits at the right hand of God. This is an awful subject; but how few of those called Christians lay it to heart!
3. The term CHURCH in Gr

Jesus said they would see the kingdom of God before their death, NOT that they would still be alive to see Jesus return.

So you misquoted it, which is why you didn’t see how it came true.

Some of the apostles did see the kingdom of God before their death, in fact they saw it right away, for, the very next passage of Scripture is the Mount of Transfiguration, where some of the apostles saw Jesus in His kingdom glory! And Jesus was also at that time standing with Elijah and Moses.

You cannot take once sentence and try to read it out of its context.
Matthew 16:24 begins
"If any of you wants to be my follower, you must put aside your selfish ambition, shoulder your cross and follow me.
16:25 If you try to keep your life for yourself, you will lose it. But, if you give up your life for me, you will find true life."

Jesus was letting them know that some of them were to die a martyrs death and that they would find everlasting life with Him, in the kingdom of heaven.