In Ephesians 4:16 and Colossians 2:19, the apostle Paul describes the church as a body. Christ is the head and nourishment flows through the body from one member to another so that all members are fed. The members are bound together by sinews that enable the body to function in a coordinated way according to the will of the head. That is the plan of God for the church, the body of Christ.
I fear that evangelism is sometimes mistaken for mission work. The preaching of the gospel to lead sinners to Christ is evangelism. But we must not stop there. A collection of converts is not a body of believers.
Mission work, as described in Matthew 28:19 is about making disciples. New converts need to be instructed in discipleship, how to be knit together in love in order to become part of the working body of a congregation.
Another way of saying this is that evangelism falls short of its goal if it is not followed by discipleship that binds believers together in a body that actively portrays the truth of our Saviour’s love and redemptive power.