Luke’s genealogy of Jesus shows Jesus humanity and history by lineage through His full genealogy in Luke 3:23-38. The genealogy traces the ancestors of Jesus, father by father, beginning with Joseph (his step-father) through King David, Abraham, and Noah all the way back to Adam. This is considered Jesus' legal genealogy. He was presumed to be the physical seed of Joseph, and that is who this line goes through and why it states "as was supposed" the son of Joseph.
Galatians 4:4- But when the fulness of the time was come, God sent forth his Son, made of a woman, made under the law,
Sometimes people want to correct his verse, but they don't take into account that Jesus was literally made of just one human's DNA. His entire human genetic material was made from Mary.
While Reu does not appear after Peleg in Genesis 10 he is listed in the genealogy in Genesis 11:18-19. He is also mentioned in Luke 3:35 as Ragau. The spelling variations can be accounted for as follows: Luke is writing in Greek, whereas Moses (Genesis) and the Chronicles are writings in Hebrew.
However, in Luke 3.36 Cainan appears as the father of Sala and the son of Arphaxad. This has been alleged to contradict the Old Testament genealogies of the ‘generations of Shem’ recorded in Genesis 10:24, Genesis 11:12 and 1 Chronicles 1:18 where Salah (or Shelah, in Chronicles) appears as the son of Arphaxad. By consulting the KJV's translation of the Old Testament, we find that this genealogy in Luke 3 almost perfectly matches the genealogies found in the fifth, tenth, and eleventh chapters of Genesis and the first chapter of I Chronicles. There is just one discrepancy, "Cainan, son of Arphaxad,'' does not appear in the KJV Old Testament.
It should be noted that While the names 'Cainan' and 'Canaan' in English look similar in Hebrew they differ, the name 'Cainan' meaning 'fixed' and the name 'Canaan' meaning 'humiliated'. The KJV translators would have noticed if this was the same name repeated a few lines later. What accounts for this discrepancy? Does Luke 3:36 have a name that doesn't belong, or did the genealogies of the KJV Old Testament leave a name out for some reason?
Cainan is mentioned in the Septuagint made long after Luke was written, the Greek translation of the Book of Genesis, the Book of Jubilees, and the genealogy of Jesus given in Luke 3:36 in the New Testament. He is described as a son of Arpachshad and father of Salah, who lived in the time between Noah and Abraham. There is a reason that certain books were removed from the KJV canon of Scriptures. It was because somewhere in them they contradicted other portions of Scripture, and they weren't quoted by early Christians (Church elders). They were considered "doubtful writings".
The Book of Jubilees, a rewritten version of Genesis and Exodus supposedly dating from 160–150 BC records a Cainan between Arphaxad and Salah. Jubilees 8.1–5 gives a rather detailed account of this postdiluvian Cainan:
In the twenty-ninth jubilee, in the first week, in the beginning thereof Arpachshad took to himself a wife and her name was Rasu’eja, the daughter of Susan, the daughter of Elam, and she bare him a son in the third year in this week, and he called his name Kainam. And the son grew, and his father taught him writing, and he went to seek for himself a place where he might seize for himself a city. And he found a writing which former (generations) had carved on the rock, and he read what was thereon, and he transcribed it and sinned owing to it; for it contained the teaching of the Watchers in accordance with which they used to observe the omens of the sun and moon and stars in all the signs of heaven.
And he wrote it down and said nothing regarding it; for he was afraid to speak to Noah about it lest he should be angry with him on account of it. And in the thirtieth jubilee, in the second week, in the first year thereof, he took to himself a wife, and her name was Melka, the daughter of Madai, the son of Japheth, and in the fourth year he begat a son, and called his name Shelah; for he said: ‘Truly I have been sent’.
According to the Book of Jubilees, Cainan was taught to read by his father, and he found, carved on the rocks by former generations, an inscription preserving the science of astrology as taught by the Watchers (fallen angels), who had rebelled from God before the flood.
Some early chronographers such as John of Antioch (seventh century AD) and George Syncellus (ninth century AD) also refer to a postdiluvian Cainan. Their accounts differ somewhat from the Book of Jubilees, so they are probably derived from independent sources. John of Antioch records Cainan’s discovery of a stele inscribed with astronomical teachings left by the descendants of Seth before the Flood. George Syncellus records Cainan’s ‘walking in the field’ and discovering the ‘writing of the Giants’ which he ‘hid...for himself ’. George Syncellus also repeatedly refers to the error of Eusebius and Africanus in omitting Cainan from their chronologies.
In The Patriarchal Age: or, the History and Religion of Mankind (1854), George Smith writes, "The Alexandrine Chronicle derives the Samaritans from Cainan; Eustachius Antiochenus, the Saggodians; George Syncellus, the Gaspheni; Epiphanius the Cajani. Besides the particulars already mentioned, it is said Cainan was the first after the flood who invented astronomy, and that his sons made a god of him, and worshiped his image after his death. The founding of the city of Harran in Mesopotamia is also attributed to him; which, it is believed, is so called from a son he had of that name."
In the Septuagint, which is written long after Luke penned his gospel, Genesis 11:12-13 reads like this:
And Arphaxad lived a hundred and thirty-five years, and begot Cainan. And Arphaxad lived after he had begotten Cainan, four hundred years, and begot sons and daughters, and died. And Cainan lived a hundred and thirty years and begot Sala; and Canaan lived after he had begotten Sala, three hundred and thirty years, and begot sons and daughters, and died.
Berosus, the Chaldean annalist of the third century BC, refers to Abraham as a ‘just man and great’ who lived ‘in the tenth generation after the flood’. Eupolemus, a Hellenistic Jewish historian writing about the middle of the second century BC, also refers to Abraham as being the ‘tenth generation’ after the flood. But it is presumed from Genesis 11:11–26 and 1 Chronicles 1:24–27 that Abraham is the ninth generation born after the flood, Arphaxad being the first generation. In Luke 3:34–36, however, with the extra Cainan in the genealogy, Abraham is indeed the tenth generation after the flood.
The Jewish historian Demetrius, who lived in the 200s B.C. around the same time that the Septuagint translation was beginning to be prepared, also included the second Cainan. The writings of Demetrius are lost, but some of his statements were preserved by Alexander Polyhistor, who lived around the time that Christ was born. Like Demetrius, Polyhistor also included the second Cainan.
But why might the postdiluvian Cainan have been omitted from the Old Testament genealogies?
The postdiluvian Cainan does not appear in the (Proto-)Masoretic Text, the most common Hebrew version of Genesis. I argue that the omission from the Masoretic text is deliberate. It is evident that Cainan discovered and revived a wickedness which ‘former generations’ practised before the Flood.
Deuteronomy 29:18, 20- Lest there should be among you man, or woman, or family, or tribe, whose heart turneth away this day from the LORD our God, to go and serve the gods of these nations; lest there should be among you a root that beareth gall and wormwood; The LORD will not spare him, but then the anger of the LORD and his jealousy shall smoke against that man, and all the curses that are written in this book shall lie upon him, and the LORD shall blot out his name from under heaven.
Genesis 6:4- There were giants in the earth in those days; and also after that,
Numbers 13:33- And there we saw the giants, the sons of Anak, which come of the giants: and we were in our own sight as grasshoppers, and so we were in their sight.
Where did the giants come from after the flood? Is it possible that Cainan was the reason for these giants, and that is why God would blot his name out of the Genesis record?
Moses, under the direction of God, blotted out his name from the genealogy of mankind most likely because Cainan had been tainted with Angelic seed or practices. we can conclude that he was not accidentally deleted in the Bible but was deleted for a purpose. This also impacted Ezra who also left his name out in the book of Chronicles. Thus, all of the Hebrew texts and those from Hebrew such as the Targum, excluded Cainan, except for Jubilees as it was providing a history. Cainan’s sin most likely was the reason there were giants after the flood, based on what he did by following the teachings of the watchers (fallen angels) which he had translated. He would have had the child, Sala, very early before this transgression (the main objective of the watchers was to pollute the seed of mankind).
Now, you should understand that the Hebrew word ‘begat’ in Genesis 10:24 and 11:12 is not confined to immediate offspring, but may refer to a descendant. For example, in Genesis 46.15 Leah is said to bare ‘thirty and three’ sons to Jacob. Now, Leah only ‘bore’ six immediate sons to Jacob, so the remaining twenty-seven evidently includes grandsons and great grandsons; and yet Leah is said to have ‘borne’ these also. This is consistent with the usage of the word ‘son’ in Hebrew. A ‘son’ may be a ‘grandson’ or even a more distant descendant.
Arphaxad more than likely raised Sala as his own. 35 years from Arphaxad to Sala as per the scripture is possible, as Cainan could have had Sala at a very young age. Obviously, Cainan’s sin did not impact this son, but only himself and those who would come after.
Also, genealogies in Scripture are for specific purposes and it is important to understand the purpose in each case. For example, in Jeremiah 22.30, ‘Thus saith the LORD, Write ye this man childless, a man that shall not prosper in his days: for no man of his seed shall prosper, sitting upon the throne of David, and ruling any more in Judah’. This was spoken of ungodly King Jeconiah. But does it mean that Jeconiah was absolutely childless? No, since it is apparent from 1 Chronicles 3.17–18 that Jeconiah had eight sons. In Matthew 1, when Christ's genealogy through his mother's side is recounted, it lists Jeconiah and the line of his descendants. Moreover, the last part of Jeremiah 22.30 itself implies that Jeconiah will have a seed, but that none of that seed will be on the throne of David and rule in Judah. He is to be written down ‘childless’ because he is ‘childless’ in respect of a royal seed, a seed ‘sitting upon the throne of David’, but not ‘childless’ absolutely. This is why there needed to be a virgin birth, the "seed" was God's, but the heritage was that of the line of the Kings of Judah and Israel.
Similarly, the genealogies in Genesis and 1 Chronicles do not record Cainan since they go from what Moses wrote and Moses was directed to leave him out. Cainan has no part in that genealogy because of his ungodliness. But that does not mean that he did not exist at all, for he is recorded in Luke’s Gospel.
So why does Cainan appear in the genealogy in the gospel of Luke? Should he not also have been excluded from that genealogy for the same reason? No, because the purpose of the genealogy in Luke is different. Luke’s genealogy is given at the outset of the Messiah’s ministry to confirm His legal credentials for the work set before Him. The purpose is not to distinguish the godly from the ungodly seed, nor to look along that godly line in hope of the Saviour to come, in which case an ungodly member of the line might be shunned as contrary to that hope. Instead, Luke’s aim is to trace a genealogical line to confirm the credentials of a Saviour already come, as ‘son of David’, ‘son of Adam’ and ‘son of God’.
It should be understood by the reader that God has caused certain details to be revealed in the New Testament in order to clarify issues in the Old Testament which are not immediately apparent. An example would be when He told Daniel to "seal up the vision and the prophecy", and then in Revelation, John was told "seal not the sayings of the prophecy of this book". You need the New Testament to open the Old Testament, and you must have an indwelling Christ to understand how they are connected.
Genealogies not matching verbatim is not exclusive to Luke. For example, in Matthew 1:8-9, Matthew eliminated three names found in the Old Testament genealogical records—Ahaziah, Joash, Amaziah. This was perhaps done for two reasons. Firstly, these men were idolaters, which Cainan may have been as well (and thus prompted the Holy Spirit through Matthew to omit them from his record). Secondly, Matthew’s intention was to make three sets of 14 generations (Abraham to David, David to Babylon, and Babylon to Christ). Those three names would have made 17, offsetting Matthew’s symmetry.
Likewise, Luke is not word-for-word with his Old Testament family trees. In fact, by adding Cainan to verse 36, the Holy Spirit through Luke totals 77 generations from Adam to Christ (thus perfectly divisible by seven, the Bible’s number of perfection or completion). Jesus is the perfect Man, “the son of” appearing 77 times in Luke 3:23-38! Eliminating “Cainan” from verse 36 to make it conform to Moses and the Chronicler, however, we have merely 76 generations in Luke. Then, Jesus therefore was not perfect or complete in His legal generations. Simply put, “Cainan” is necessary in Luke 3:36; it was Luke’s original writing, and therefore belongs.
Since Matthew skipped some names to provide only three sets of 14 generations in his genealogical records, surely, we can: (1) permit Moses and the Chronicler to intentionally skip one name in their respective Books, and (2) allow Luke to insert that name not found in the Old Testament in order to show Jesus’ perfection. The Holy Spirit superintended all these men, so we need not question the infallibility of their writings.
When in doubt, give God the credit. We need not sacrifice Bible inspiration, infallibility, or preservation: all we need to do is adjust our thinking to better understand Moses’ handling of the family tree in Genesis chapters 10 and 11.
Remember, Jesus is David’s “son” and David is Jesus’ “father,” but this is in the sense of great-(40X) grandson and great-(40X) grandfather. The sense is forefather and posterity, with a millennium separating them, but still an unbroken bloodline nonetheless.
Old Testament Jewish genealogies focused on biological sonship. However, the genealogy of Luke clearly focuses on sonship by adoption. Luke 3:23 says that Jesus was “the son of Joseph” despite Joseph having no biological connection to Jesus. Jesus was the adopted son of Joseph. If this pattern continues in the genealogy, it would not be surprising to find an adopted son who had previously been omitted from biological genealogies. We can reasonably accept that Sala was the adopted son of Arphaxad, and that Arphaxad raised Sala, who was the biological son of Cainan.
A better way to look at Luke 3:36 is simply to see it as progressive revelation. The Holy Spirit caused Moses and the Chronicler to skip Cainan’s generation when recording family information (reason unknown) but had Luke write it because Luke was focused specifically on Jesus being Israel’s Messiah perfect in His 77 generations. Without Luke, we would have never known a Cainan existed between Arphaxad and Salah.
If you ever find yourself pointing out errors in the KJV Bible, perhaps you need to get on your knees and ask God to open your eyes to the truths that He is trying to make apparent through these differences. You may just get a biblical revelation from God Himself!