XXXV. Chapter Six of Jesus of Nazareth pauses the Gospel narrative to consider the disciples of Jesus. While the invitation to the Kingdom Jesus came to establish is universal, it is clear in His earthly ministry that He “calls an inner core of people specially chosen by Him, who are to carry on His mission and give this family order and shape” (p. 169). With minor variations, the Gospels agree that the core of this core is the Twelve Apostles.
Mark tells us that Jesus moves from the “lake,” the scene of earlier miracles and teachings, to the “mountain.” This signifies the place of His communion with the Father, a place on the heights above everyday life. Luke underscores this by noting that the call of the Twelve came after a night spent in prayer to God. Something decisive occurs with the choice of the Apostles. They are not simply companions of Jesus, but chosen by Him. This is a reversal of the usual Jewish practice (seen even today when people select a parish community) – the disciples selected a rabbi to follow; the rabbi did not select his followers. Yet Jesus does just that, and thereby shows that being His disciple is a matter of election, a free decision of the Lord’s love.
Mark goes on to say that Jesus appointed twelve of His followers and called them apostles. The Greek literally says not "appointed" but "made" - in the background is the Old Testament terminology for appointing priests. In this subtle way, Mark makes the point that the Apostles are also chosen for priestly ministry; and by listing their names, Mark also links them to the prophets, who are called by name. They are to be priests, prophets, and kings - in the same sense that Jesus's kingly role is shown by His sacrificial service.