Yeshua tells His Talmudim (Disciples, or students), and also mentions throughout the Gospels, that some of this generation will see the kingdom of God come:

Matthew 16:28- I tell you the truth, some who are standing here will not taste death before they see the Son of Man coming in his kingdom.

Mark 9:1- And he said to them, “I tell you the truth, some who are standing here will not taste death before they see the kingdom of God come with power.

Luke 9:27- I tell you the truth, some who are standing here will not taste death before they see the kingdom of God

If we took these statements literally, it would mean that at least some of the people He talked with would see what we expect from Revelations, i.e. the new heaven and the new earth, with the Temple coming down from the sky. But none of that happened then, and in fact, hasn’t happened even to this day.

Clearly, there must be a deeper meaning.

Judaism and Christianity both believe the number 7 has special significance, in that it represents completion; this comes from the 7th day being Shabbat (the world was completed in 6 days and on the 7th day God rested.) God told us to rest on the 7th day, after which we start to count the days until the next Shabbat, so we can draw from this that even though the world was created in just 6 days, God sees the 7th day as the completion of that cycle.

Further along on this thought, there is a belief in Judaism that the world is going to last for 6,000 years (Talmud-Sanhedrin 97a), and at that time (if the Messiah hasn’t come before then) the Age of Messiah will begin with the 7,000 year. The reason we wait 6,000 years is based on the 7th day Shabbat and this verse from the Psalms:

Psalms 90:4– For one thousand years in Your [God’s] eyes are but a day that has passed.

Let’s look at the biblical history of mankind: God created people through Adam and Eve, and all but 8 of them died out in the Flood. Then an entirely new race of people came from Noah and his sons. Can’t we call this a new generation of human beings? The next destruction of human beings, namely this current post-Flood generation, will occur with the Tribulation when all living and dead human beings will be judged, with the righteous (saved by Messiah) being resurrected with a new body, and the doomed going to the Lake of Fire and eternal damnation.   Therefore, we are a generation of people with finite lifetimes, which will be completely different after the final Judgment, when we will be beings of eternal life. A new, third generation.

Therefore, I believe what Yeshua meant when He said some of this generation will not pass away until they see the Kingdom of God come will be of those people who have lived between the Flood and the Tribulation. In the bible we have people who existed before the Flood (the first generation), then the people that repopulated the earth after the flood (the second generation, which is the current one), and there will be the third generation, composed of those who survive the Tribulation and are resurrected by means of their faith in Yeshua.

The number 7 represents completion, but so does the number 3. This is why I see God’s plan for His creation completed in the  7th  Millennia with the 3rd generation.

A completed creation, earth and people, that will last for eternity.