When reading the genealogy of Jesus in the Gospel of Luke, you’ll find that Shelah’s father was Cainan, however, a genealogy in Genesis 11 states that Arphaxad was his father.  Is this a contradiction? Let’s first look at the verses.

‎(Luke 3:35-36) ” the son of Serug, the son of Reu, the son of Peleg, the son of ‎Eber, the son of Shelah, the son of Cainan, the son of Arphaxad, the son of ‎Shem, the son of Noah, the son of Lamech”‎

(Genesis 11:12) ” And Arphaxad lived five and thirty years, and begat ‎Salah”‎

A few plausible explanations explain why the genealogy of Luke includes a name that never appeared in any Jewish genealogy, including Genesis, Chronicles and the historian Josephus. You see, previous Jewish genealogies focused on biological sonship. However, the genealogy of Luke clearly includes sonship by legal 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. Another case of this legal adoption is found in the instance of Joseph’s biological father, Jacob (Matthew 1:16), and legal father, Heli (Luke 3:23). ‎In this instance, it’s possible Heli and Jacob were half-brothers, and when Heli died childless, his brother needed to provide him with an heir as was prescribed in Deuteronomy:“When brothers dwell together and one of them dies without a son, the widow must not ‎marry outside the family. Her husband’s brother is to take her as his wife and fulfil the duty ‎of a brother-in-law for her.” (Deuteronomy 25:5, NKJV).‎

As this could indicate a pattern in the genealogy, it should not be surprising to find an adopted son who had previously been omitted from biological genealogies. We can reasonably accept that Cainan was the adopted son of Arphaxad, and that Cainan raised Shelah, who was the biological son of Arphaxad.

Another explanation involves the Septuagint. The Greek Septuagint (LXX), an early translation of the Hebrew Bible, includes Cainan in ‎Genesis 11:12, stating that Arphaxad begot Cainan, and Cainan begot Shelah. This aligns ‎with Luke’s genealogy, suggesting that Luke may have been relying on the LXX rather than ‎the Masoretic Text (MT). However, the Masoretic Text (MT)—which became the standard ‎Hebrew text—omits Cainan entirely.‎

The Dead Sea Scrolls (DSS) fragments of Genesis do not include this portion, so it is unclear ‎whether they originally contained Cainan. The Samaritan Pentateuch (SP), another ancient ‎textual tradition, follows the MT and omits Cainan. ‎

Biblical genealogies often use “telescoping,” where intermediate generations are skipped to ‎highlight significant figures. The omission of Cainan in Genesis might be an example of this ‎practice, simplifying the lineage by naming only the most relevant ancestors. This is ‎common in Jewish genealogies, as seen elsewhere in Scripture (e.g., Matthew 1, which ‎omits some names from Old Testament genealogies).‎

Since Luke was writing in Greek and often quoted from the LXX, it is likely that he followed ‎the genealogical tradition found in the LXX rather than the MT. If Luke included Cainan ‎because it was in his source material, he may have assumed it to be an authentic part of the ‎genealogy. ‎

From a theological standpoint, this discrepancy does not challenge the reliability of ‎Scripture but rather highlights the complexity of textual transmission. ‎

Here are two points which are important to understand:‎

‎1. Different Biblical Manuscripts Preserve Different Traditions

The presence or absence of Cainan depends on whether one follows the LXX or MT ‎textual tradition. Both traditions were used by Jewish communities before and ‎during the time of Christ.‎

‎2. Genealogical Lists Were Not Always Strictly Sequential

Ancient genealogies were not necessarily intended to list every single generation. ‎The Bible sometimes condenses genealogies for theological or literary purposes.‎

Therefore, it’s entirely possible that the verse in Luke mentioned ‎the direct father and Genesis mentioned ‎the ‎distant father.‎