As we move into the second half of advent, the readings change and become more about who Jesus is as opposed to his coming. Matthew gives a genealogy of Jesus from the time of Abraham right down to his birth.
Genealogies were used to show a person's status and in this case Matthew was showing the Jesus was the direct descendant of Abraham, "our father in faith." Such a claim was important because Abraham was the father of the Jews and Jesus was the founder and leader of the new Jewish people, the ones to whom the messiah had come.
Matthew is showing the continuity of how Jesus fulfills all the conditions of the Old Law. The Christian church was beginning the process of separation from the Jews and they were being driven out of the synagogues. Matthew wanted to show the young Church and us how Jesus was related the whole way down through his ancestry to Abraham and David.
images from: pgfracing.com &