Dever argues based on John 13:34-35 that
our Christlike love for one another is intended by God to be the church's most powerful tool for evangelism. This is the reason that depending on a program for evangelistic effectiveness is a little like outsourcing the main responsibility of the church. Evangelism programs are not necessarily or categorically bad. Some are quite good. But I fear we sometimes depend on them so much that we forget that the church itself is God's evangelism program. The mutually loving relationships in the church are designed by God to be attractive to an unbelieving culture. The covenantal, careful, corporate, cross-cultural, and cross-generational love that is to characterize the church and glorify God is at the same time intended to evangelize the world (112).