The main passage likening the Church to the human body is 1 Cor. 12:14–31, describing how each part fulfills its own function in a healthy body. But notice in v. 28 that this passage pertains to in-reach (within the local church), not outreach (evangelism). There is no mention of evangelists here because it is in the context of the Church coming together; when all those functions are working well, we have a healthy Church. Then, when the Church is healthy, it will (as one body) do what it has been commanded to do by the Head: to reach out to the lost.
We are like survivors in a lifeboat of the Titanic. All around us are drowning people. We need every hand onboard to help reach those who are dying and pull them into the boat. We think and move as one mind and one body. Nothing else matters. Love is our motivation. Every hand is needed—because there is a terrible lack of rescuers. Why? Because some think their role is to sit in the lifeboat, and, knowing that people are perishing, busy themselves polishing the brass.
If that’s the case, one has to question if they are really part of the body, because the Head has commanded us to reach out to those who are perishing (see Mark 16:15). A hand that doesn’t do what the Head commands it to isn’t healthy.
As we reach out to people, we must also be sure to do it the way the Bible instructs us to. Otherwise, we are just pulling corpses into the boat—and we see the fruit of this within the contemporary Church.
1 Corinthians 12:14 For in fact the body is not one member but many.