NOTES for Mar 3:7-19
In Mark, the choosing of the apostles is shown as part of the Savior's earthly ministry, His earthly path. The main emphasis is on healings and cleansings, which is no surprise: healing and liberation from dark powers are the chief manifestations in the fallen world of the Kingdom, of its breath, of its power. Against such a background, the meaning of the apostles' calling and the meaning of their ministry become especially clear.
"Apostle" literally means "messenger." In Gospel times, the ministry of apostles was communal: as a rule, they were representatives of a particular community, sent to others in order to bear witness to something important that had happened in the community that sent them. It could be a miracle, an important prophecy, or in general some event whose spiritual significance went beyond the limits of the community where it had taken place.
In this case, that event was the coming of the Messiah and the fact that the Kingdom, according to His own word, had "drawn near." This Kingdom that had drawn near, ready to enter our world, was the main event that the apostles sent by Jesus were to announce. Words alone, however, were not enough: they had to testify by deed that the Kingdom really was near.
Those deeds were the healings performed by the apostles through the power of their Teacher, for they testified that the power of the Kingdom belongs not only to the One who brought it into the world, but that it can be manifested through everyone who has a share in the Kingdom and its life. If only the Savior Himself could perform miracles and healings, that would mean that He, as the God-man possessing an utterly unique nature, had brought into the world something that could truly belong only to Him and to no one else.
But if His disciples can perform the same miracles and healings, that means they too can become inhabitants of the Kingdom. Of course, according to the measure of their human fullness, they can become like Him and can live one life with Him, a life that will not differ qualitatively from His life. Such a prospect opened the possibility not merely of a person's temporary participation in the life of the Kingdom, but of the complete transformation of human nature itself, which would make a person an inhabitant of the Kingdom not only by participation, but by nature. This means that the Kingdom and its life will be given to man not for a time, but forever.