Q: Why is Jesus’ genealogy placed between his baptism and his temptation in Luke?
A: Luke includes Jesus’ genealogy at the beginning of his ministry. It differs from the one Matthew includes in several ways. Luke’s listing starts with Joseph and works backwards all the way to Adam “the son of God.” Matthew’s starts with Abraham and works forward. Luke emphasizes that this Messiah descends from Adam and so is related to all the nations.
Luke’s placement of the family tree connects God the Father’s statement at Jesus’ baptism (“You are my beloved Son; with you I am well pleased.”) with the indwelling Spirit of God which leads Jesus into his time of desert temptations.
Q: Where in the Bible does it say Jesus called them by name?
A: I hope I can get at your question with this answer. In Mark 3:13-19, we are told Jesus “called to him those whom he desired, and they came to him.” Namely the 12 apostles. The word “appointed” is used in this passage, “so that they might be with him and he might send them out to preach and have authority to cast out demons.” This is pretty specific. We know there were many more disciples, both men and women. Luke 6:13 and following has a parallel passage, and uses the phrase “he called his disciples and chose from them twelve, whom he named apostles.” Then Luke goes on to name the 12. Luke 9 records a specific time these 12 are sent out, and in Luke 10 Jesus sends out 72 others with instructions on proclaiming the coming kingdom.