The assembling of the disciples around Jesus as Israel’s Messiah, the one who will bring heaven and earth, was the result of the testimony of John, the invitation of other disciples, and the call of Jesus. So, the assembling of the disciples is the result of a couple of things: First, the testimony of John, the invitation of another disciple, and finally, the call of Jesus Himself. These are the things that make up the way in which disciples come to follow in the story that John is telling.