The introduction of the author Mark to his gospel:

After the heading in 1:1, the overture 1:2-20 has the task of setting the mood for the whole poem and especially the 1st part.

Mark knows how to connect the three traditions of the Jewish Christians, the Baptist Christians and the Peter Christians (who emphasize the reception of the Spirit, Acts 2:2.14) in such a way that all Christians can feel represented.

This happens not least through the calling of the disciples who establish the four original Christian groups: Simon Peter, Andrew (representing the Greek followers of Jesus), James and John, 1:16-20.