Though this text, which concerns the mother and brothers of Jesus, is found also in Mark 3:21-22 and 3:31-35 and Matthew 12:46-50, Luke narrates it quite differently from both. In Mark 3:33 and Matthew 12:48 Jesus asks who his mother and brothers are. In Luke, however, Jesus does not ask this question, but says simply when told that his mother and brothers desire to see him, that his mother and brothers are those who hear the word of God and do it. Luke thus gives a positive thrust to the scene unlike Mark and Matthew. It might be said that while in Mark and Matthew Jesus seems to reject his physical family and choose instead the crowd (so Mark) or his disciples (so Matthew), in Luke he does not do so. This means that though family relations with Jesus are not based on physical relations but on the word of God, his physical family does indeed hear the word of God and acts on it.
We might possess the name Christian because of our baptism, but this does not necessarily mean that we belong to the family of Jesus. In order to belong what is also necessary is putting into action what Jesus has taught.