Much of the misunderstanding surrounding these genealogies results because we are reading them in modern English and in the context of modern western culture. The genealogies were written in ancient Hebrew and represent ancient Jewish culture. For one thing, the Hebrew word for “son” (ben) can mean “son”, “grandson”, “great grandson” or “descendent”. And, likewise, “father” (Hebrew ab) can mean "father", "grandfather", "great-grandfather" or "ancestor". For example, in Genesis 28:13, God says to Jacob, “I am the LORD the God of your father Abraham and the God of Isaac”. But Abraham wasn’t the father of Jacob. Isaac was the father of Jacob. Abraham was the father of Isaac, thus making Abraham the grandfather of Jacob. That being said, however, the verb used in Genesis 5 and 11 is the Hebrew “yalad” and is translated “became the father of” in the NIV and “begat” in the KJV. So, it does not even use the word “father” (ab), but rather “yalad” (which is similarly flexible in its meaning). This verb can mean giving birth to someone who is ancestral to the next person named (with many generations skipped). One example of this is the genealogy of Moses in Exodus 6. These genealogies report that Amram and his wife Jochebed “begat” (Hebrew yalad) Moses (two times) and refers to him as “son” (Hebrew ben). Thus, on at least two occasions, it uses the very same verb as used in Genesis 5 and 11. But what is important to notice here is that Amram and Jochebed lived at the time when the Jews entered Egypt while Moses was 80 years old during the exodus some 430 years later. This entails that approximately 350 years (and likely a minimum of 6 generations) lies between Amram/Jochebed and Moses. Thus, literally, it should be rendered ‘Jochebed begat a son (unnamed) who was ancestral to Moses’.
For a thorough discussion of this fascinating topic, I refer readers to this excellent paper by Dr. John Millam. The article lists the following examples where one can definitively say that the genealogies have been telescoped in this manner:
- "Matthew 1:8 compared to 2 Chronicles 21:4-26:23
Matthew 1:8 has Jehoram listed as the father of Uzziah but there were several generations between these men. The names Ahaziah (2 Chronicles 22:1), Joash (2 Chronicles 22:11), and Amaziah (2 Chronicles 24:27) come between Jehoram and Uzziah.
- Matthew 1:11 compared to 2 Chronicles 36:1-9
In Matthew 1:11 we read that Josiah is the father of Jeconiah (Jehoiachin). In 2 Chronicles, we see that Josiah is the father of Jehoiakim (2 Chronicles 36:4) and grandfather of Jehoiachin (2 Chronicles 36:8).
- Luke 3:35-36 compared to Genesis 10:24, 11:12; 1 Chronicles 1:24
Luke contains the name Cainan between Shelah and Arphaxad that is missing in Genesis 10:24 and 11:12 and 1 Chronicles 1:24. Since all of the genealogies are true and Luke is the one with more names, then Luke must be more complete and the rest more telescoped.
- Ezra 7:1-5 compared to 1 Chronicles 6:3-15
The genealogy of 1 Chronicles 6:3-15 lists the descendents of Aaron down to Jehozadak (Jozadak). Ezra 7 lists Ezra’s own genealogy going back to Aaron. Where the two genealogies overlap, 1 Chronicles contains 22 names and Ezra contains 16 names, making Ezra’s genealogy no more than 70% complete. Both genealogies span a time period of about 860 years from the exodus to the fall of Jerusalem, which suggests that both genealogies are in fact highly telescoped. A thorough search of the Old Testament reveals that there were many high priests during this time period who are not included in either of these two genealogies, which provides additional evidence that these genealogies are not complete. The following high priests are known from the OT but are not included in these genealogies: Jehoiada (2 Kings 12:2), Uriah (2 Kings 16:10-16), possibly two Azariahs (2 Chronicles 26:17, 20; 31:10-31), Eli (1 Samuel 1:9; 14:3) and Abiathar (2 Samuel 8:17).
- 1 Samuel 16:10-13 compared to 1 Chronicles 2:13-15
In the 1 Samuel passage, the prophet Samuel goes to Jesse to anoint one of his sons as the new king of Israel. Jesse has his seven eldest sons pass before Samuel but each is rejected. Finally, David, the 8th son is brought in and is anointed by Samuel as king. We find in 1 Chronicles, however, that David is listed as the 7th son of Jesse. One of David’s brothers is omitted from the list to allow David to occupy the favored 7th position. This may seem a bit odd to modern readers but this was an accepted genealogical practice."
One question which often comes up is the literary construct of the genealogical reports. For example, according to Genesis 5:9-11, “When Enosh had lived 90 years, he became the father of Kenan. And after he became the father of Kenan, Enosh lived 815 years and had other sons and daughters. Altogether, Enosh lived 905 years, and then he died.” Some have suggested that the understanding, proposed above, of Biblical genealogies faces difficulty in accounting for the fact that the text would still read: “When Enosh had lived 90 years, be became the ancestor of Kenan…Enosh lived 815 years and had other descendants.” The dates, it is argued, would remain unchanged, even when considering this interpretation - whether Enosh became the father or ancestor of Kenan at age 90, it is argued, is irrelevant to the calculation. In light of what I have tried to show above, however, it is my view that the correct rendering of the text runs along the lines of: “At age 90, Enosh gave birth to a son whose descendants would include Kenan.” Thus, the 90 years refers to when Enosh became a father, not when Kenan was born. While this may seem very peculiar (or even wrong) in English, one must always keep in mind that we are dealing with an ancient Hebrew genealogy.
In conclusion, to try to place dates on Biblical events, squarely on the basis of the genealogies alone, faces significant obstacles, and springs from a misapprehension of the nature of ancient Hebrew genealogies. It is also important to bear in mind that this argument does not concern or address the age of the earth (nor, for that matter, the proper interpretation of Genesis 1). Rather, all it shows is that the Christian need not feel committed, as many contend that we are, to placing the creation of Adam roughly 6,000 years ago. Moreover, such a conclusion may be accepted by young-earth and old-earth advocate alike (I personally fall into the latter of those camps). On the flip side of the coin, the non-believer need not be turned off Christianity by the apparently extremely recent origin of modern humans. There is simply no compelling Biblical mandate for supposing that this is the case.