Johnson argues that Pentecostals are no longer clear in their understanding of mission. He suggests that the shift in thinking about mission from pioneer evangelism and church planting to a supportive role among already existing church movements has come in part because of the great success of Pentecostal mission. The lack of a theology of success coupled with an emphasis on responsive peoples has hindered the ability of Pentecostals to see the resistant and those most separated from the gospel. Johnson advocates we revisit a theme important to early Pentecostals who saw themselves as part of a restoration of apostolic power and practice. He conceptualizes this in the notion of 'apostolic function' by which he means a focus on the apostolic task of preaching the Gospel where it has not been heard, planting the church where it does not exist, and leading people to the obedience of faith.