This discussion is valuable here because Luke and Matthew were writing to an audience who had either heard about the Messiah or were still expecting the Messiah. Expectations of where he would come from influence the context or focus that Luke and Matthew may use. The expectations of the Messiah are twofold. One is from Scripture, the other from the people.
The Gospels constantly show that the people’s expectations are almost always off the mark. The expectations of Scripture on the other hand are always fulfilled in Jesus. Although the people expected the Messiah to be physically from the blood of David, one must not be too quick in dismissing this view. The Scriptures are difficult to interpret any other way. In Genesis 15, Abraham considers his chief servant to be his heir in the absence of a child. This relationship could easily have been considered an adoption in his culture. Yet, legitimate as this would have been culturally, God makes it clear that this is not what He has in mind. God states that his heir would come forth “from your own very being” in direct contradiction to a figurative sonship. This is the strongest language that could be used to show that Abraham’s own body would produce an offspring. Genesis 15 does not necessarily incorporate the ‘seed’ promise directly, but of Isaac specifically.
The matter becomes more decisive, however, when 2 Samuel 7 is considered. God makes the messianic promise to David and uses the same words, “from your very being.” If God intended for Abraham’s seed to be a direct blood line, there is no indication that this same promise to David should be thought about in any other way. Peter has the same surety of Jesus’ relation to David by quoting Psalm 132 in his first sermon in Acts 2. Peter first calls David Jesus’ patriarch and then quotes the saying, “God swore with an oath to him to seat one of his descendents on his throne.” The actual passage in Psalm 132:11 says, “the Lord has sworn to David a truth which He will not turn back: ‘Of the fruit of your body I will set upon your throne.’” It is hard to argue in this light that the Scriptures expected anything less than the Messiah to come from David’s own body.
Now it is certainly possible that Matthew’s genealogy was purely legal succession and so did not have to coincide at all with Joseph’s actual line. If Joseph was from Shealtiel then he came next in line. The biggest problem is that if the Jews were keeping such ‘legal’ tabs on people, then why did it surprise them that Jesus was the son of the carpenter? If Joseph was next in line to the throne, then they would have had little doubts about Jesus’ Messiahship. Yet they doubted his Messiahship explicitly because he was so unknown. Matthew’s list is proof of kingship against the popular opinion. For there to be two genealogies kept in tact (one of Joseph, and one of the legal heir) would imply a greater significance to the title of King than the people gave Joseph credit for. Since they did not appear to keep such royal tabs on people, it suggests that Matthew’s may just be a humble account of the firstborn rights within the kingly line. This information was not capitalized on during Jesus’ day, which makes it less likely that it was stressed enough to present as an independent genealogy of legal rights. It may be that the last of Jacob’s line was dwindling and Joseph inherited the title by default without much ado. But I doubt based on Matthew’s context and his aptitude to complex authoring that he intended to convey a fluke of title inheritance.
The significance of the previous thought is this: why would the Jews keep a literal line of Joseph and a legal line of Joseph if they were going to culturally ignore it in the face of Jesus’ legitimacy? Logic would direct us to a conclusion that includes the Jewish expectation about the Messiah along with the scriptural view. The people behave towards Jesus and Joseph as menial lower class workers. The Matthew genealogy, then was either not produced, or not as important to the Jews as Matthew stressed to his readers. If they understood Joseph’s line to be “legal” and not literal, they may have only seen Joseph as a physical option for kingship, not a legitimate forefather to “the Messiah.” These doubts may have influenced their hesitancy in accepting Jesus.
The Jewish expectation of the messiah was very literal and physical. This physical blood line lent to their expectations of the physical kingdom. God has a knack of turning physical expectations into spiritual realities. It should not surprise us if God chose to switch gears to a spiritual light. One must keep in mind that spiritual does not necessarily mean figurative any more than figurative means “not-real.” The Messiah was very real, and is literally the king of God’s spiritual people. It turns out that God also stressed a physical descendency through David. The scriptural expectation of the Messiah’s origin was equally as physical. There was a need for Jesus to be born in Bethlehem, there was a need for him to visit Egypt, and there was a need for him to be called a Nazarene. For once, the Jewish expectation was God’s as well.