There is no problem. Jesus said it. Therefore it must be true. ;) :)
Well let's take a look at this statement that you agree is true.
The Greek word for generation is Genea. Strong's number 1074; noun whose original meaning was generation, that is, a multitude of contemporaries. In NT Gr. genea literally means space of time, circle of time, which only in a derived sense signifies the meaning of a time, a race; then generally in the sense of affinity of communion based upon the sameness of stock. Race or posterity (Acts 8:33). Generation (Matthew 1:17), occurs with special reference to the physical or moral circumstances, speaking of an age or time referring to the spiritual state of society at the time (Hebrews 3:10, cf. Luke 7:31; 11:31; Acts 13:36). The connection alone must decide whether the sense is limited to the state of society at a certain time or to race or stock. The word genea in Matthew 24:34 meant the type of Jew with whom Jesus was conversing during that particular time (Matthew 21:23; 23:29). He was telling them that this generation or type, such as the Sadducees and Pharisees of that day, would not pass away until all these things occurred and until His coming again in His parousia (Strong's 3952), Second Coming. He was prophesying the destruction of their nation (Matthew 24:15-28) (emphasis mine, reference The complete New Testament Word Study by Spiros Zodhiates, Th.D.)
So understanding in context what the word generation means we can see that Jesus was not talking specifically about those saints he saw and was speaking to face-to-face. Add to this what Jesus said prior about the specific signs in the heavens, the gatering of his elect, and the parable of the fig tree we can be certain that he was not speaking of the contemporaries of Peter and James.
And then let's take a look at what Jesus had to say after "this generation shall not pass, till all these things be fulfilled." He spoke of two being in the field or grinding at the mill and one being taken and the other left. Where in history do we have record of something of this uniqueness happening? Do you not think our history books (biased as they may be) would not mention this phenomena?
Common sense (although not so common anymore) and good study makes it pretty obvious that these events spoken of by Jesus have not occurred just yet.
1Co 7:31 and those that use the world, as not using it to the full: for the fashion of this world passeth away.
Rom 13:11 And this, knowing the season, that already it is time for you to awake out of sleep: for now is salvation nearer to us than when we first believed.
2Ti 4:1 I do fully testify, then, before God, and the Lord Jesus Christ, who is about to judge living and dead at his manifestation and his reign--
Jas 5:8 Be ye also patient; establish your hearts: for the coming of the Lord is at hand.
1Jn 2:18 Little children, it is the last hour: and as ye heard that antichrist cometh, even now have there arisen many antichrists; whereby we know that it is the last hour.
Rev 1:3 Blessed is he that readeth, and they that hear the words of the prophecy, and keep the things that are written therein: for the time is at hand.
Rev 3:11 'I am coming quickly! Be holding fast what you have, so that no one shall receive your victor's wreath.
Rev 22:7 "{And} listen! I am coming quickly! Happy [is] the one keeping the words of the prophecy of this scroll."
Rev 22:12 "Listen! I am coming quickly, and My reward [is] with me, to render [or, repay] to each as his work will be [fig., according to his deeds].
Rev 22:10 And he says to me, "Do not seal the words of the prophecy of this scroll, {for} the time is near.
Rev 22:20 The One testifying to these things says, "Yes, I am coming quickly!" So be it! Yes, be coming, Lord Jesus!
You might want to explain away those also. Those are the letters they sent back and forth to each other 1950 years ago. They were "eagerly" awaiting the return of Jesus (Php 3:20). Why? Because Jesus told the disciples he was coming back for them (Joh 14:3). Thus he surely did. :)
“Genea: From (a presumed derivative of) genos; a generation; by implication, an age (the period or the persons) — age, generation, nation, time.
Genos: Kin. from Ginomai
Ginomai: to cause to be, be brought to pass, happen”
The idea is that Genea refers to those who lived contemporaneously with one another.
A general word of caution: Strong’s is not meant as a translation tool. To use Strong’s definitions to support a given interpretation is merely to appeal to an authority — Strong. His definitions are based on how he sees them used in the bible, and have precisely nothing to do with their actual usage in Greek or Hebrew, outside of the bible.
Worse, he lumps all related words together. In this case, that causes no particular harm.
YOU HAVE THIS HABIT OF BEING ABSOLUTELY CORRECT ABOUT SUCH MATTERS.
THANKS.