What is a Biblical Generation?
“And the Lord’s anger was kindled against Israel, and He made them wander in the wilderness 40 years, until all the generation that had done evil in the sight of the Lord, was consumed.” (Numbers 32:13) This indicates that a generation is 40 years. (It could possibly suggest that a generation is simply the length of the average lifespan, thus longer than 40 years.)
“And after this Job lived 140 years, and saw his sons, and his sons’ sons, four generations.” (Job 42:16) This passages pretty clearly suggests a generation to be about 35 years.
“For 40 years I loathed that generation.” (Psalm 95:10) Similar to the above, it indicates a generation as being 40 years.
“where your fathers put me to the test and saw my works for 40 years. Therefore, I was provoked with that generation.” (Hebrews 3:9-10) This is pretty clear and consistent with most passages in the Bible. A biblical generation is 40 years.
“On YOU may come all the righteous blood shed on earth, from the blood of innocent Abel to the blood of Zechariah and the son of Barachiah, whom you murdered between the sanctuary and the altar. Truly I say to you, all these things will come upon THIS GENERATION.” (Matthew 23:35-36) Here Jesus is speaking to his contemporaries and without doubt He meant that this judgment would be before some of them had died. See also Matthew 10:15, 23; 16:27-29; 24:34. This judgment befell them in AD 70, about 40 years later.
In the genealogical table of Matthew 1:17, we have data to estimate the length of a generation. There are three fourteen-generation periods. Scholars disagree on just how literal these are as Matthew may have included the most important people to make it a symmetrical rendering. But the clearest is the fourteen generations from the captivity in Babylon until Christ. The date of the captivity, in the reign of Zedekiah, was 586 BC. From 586 BC until the birth of Christ would be appx. 583 years which, divided by fourteen, makes the average length of a generation about 41 years.
Some Christians cite Psalm 90:10 which says, “The years of our life are seventy, or even by reason of strength eighty.” But that is about lifespan, not generation. A generation is more about the average age of having children.
Conclusion: A biblical generation is pretty consistently 40 years. In prophecy, the New Testament uses the term “this generation” at least 17 times, including those mentions in the Olivet Discourse.
To what time-period does the phrase “this generation” in the New Testament refer? It is used in the Olivet Discourse (Matthew 24:34, Mark 13:30, Luke 21:32) in reference to the fulfillment of end times prophecies. A straight-forward reading of the text indicates that these prophecies would be fulfilled while some hearing Jesus’ words in the first century were still alive. To confirm that it refers to the first century contemporaries of Jesus we need only to look at the other times the phrase is used in the New Testament. Without doubt, it ALWAYS refers to those living in the first century. No other conclusion is possible without doing violence to the text. Here are all the times the phrase is used outside of the Olivet Discourse. Look up these passages for yourself:
Matthew 11:16-24; 12:38-45; 16:4; 17:17; 23:35-36; Mark 8:12; 8:38-9:1; 9:19, and Luke 7:31; 9:41; 11:29-32, 49-51; 17:25; Acts 2:40.
The certain conclusion is that the “end times” is not about the end of the physical universe, not about the end of the Christian age, and not about anything in our future. It is about the end of the Old Covenant age, which ended with the fall of Jerusalem and destruction of the temple in AD 70.
For more on this, see my article entitled “When Was the Olivet Discourse Fulfilled?” here: