Awhile ago, I corresponded with a member of our congregation on the subject of Christ’s genealogy from the book of Ruth. I requested their permission to post the ‘results’ here as an example of a question that someone might wish to ask. The question is posed first and then my answer is included below it.
R: The line of Christ is given as Nahshon, Salmon, Boaz, Obed, Jesse. That is the line of Christ came through Boaz. In the story of Ruth, Boaz is presented as a kinsman redeemer. As I understand the title, Boaz was to perpetuate the line of the deceased branch of the family. To this end the firstborn son was considered heir to the dead. Should not the line of Christ include Elimemelch and Mahlon?
Pastor: My assumption would be that since the purpose of a kinsmen redeemer would be, as you said, to perpetuate the line of the family that Boaz would be given the honor of his name being included in the genealogy especially since Mahlon and Elimelech had been unfaithful (having left the promised land for Moab and living there for some time without returning to Israel; Mahlon marrying outside of the covenant house of God). That is their names were ‘erased’ from the line and replaced with Boaz. Besides Ruth had no children through Mahlon but only by Boaz. So at the very least Mahlon should not be included since he was never a father and the line of the covenant is usually through the father (Abraham, Isaac, Jacob etc.). This does not account for Elimelech but as we examine the genealogy at the end of the book of Ruth we see that the author is tracing a new, Davidic line more than trying to explain what happened to the other line. The same thing, albeit more broader, is communicated in Matthew. Matthew wants to account for the Judaic line of Christ through David; Elimelech, though of the house of Judah, does not need to be mentioned in order to prove the Davidic descent of Jesus since, technically, He did not descend from Elimelech since Ruth was not his biological daughter and Boaz was not his biological son.
The other consideration, and one that I have not verified or am fully persuaded of yet, is that Matthew’s genealogy is intentionally not complete (or not thorough) but symbolic since there are 14 generations from Abraham to David and 14 generations from David to Babylon and 14 from Babylon to Christ (14 = 2 x 7, 7 being, of course, a number of perfection or holiness). 40 years for a generation x 42 generations = 1680 which does not really account for the 2000 or so years that are between Abraham to Christ.