One of the shifts in movements is in ideas around the speed of discipleship.
Some critics equate “rapid expansion” with getting a person shallowly saved, and then moving on. The reality on the ground – both in the West and among movements – is actually quite different.
Most believers in traditional churches grow up in the church; those that convert to Christianity are a result of a context of friendships with believers and/or a spiritual crisis. Global statistics generally indicate about 45 million believers are born into the church worldwide, and 15 million are converts. Far more are the result of long-term “growing up” discipleship of Christian families. (Yes, there is the issue of fall-away–I’m not going to deal with that at the moment.)
Believers in movements typically come in as a result of conversion (not demographic growth), since many if not most movements are in contexts of non-believing populations. These conversions result from an initial study of Scripture stories often coupled with some form of power encounter that meets a need. A typical story one hears is of healing, deliverance, or another form of need being met, coupled with a “Jesus-did-this-would-you-like-to-hear-more-about-him,” followed by a set of times reading Scripture stories (“Creation to Christ,” often) about Jesus, followed by a moment when one chooses to follow Jesus and eventual baptism.
The net result is that in movements, there is often far more discovery of who Jesus is prior to conversion than there is for converts in the West – this discovery is probably more akin to people who grow up in the church and hear Bible stories, etc as they are growing up.
Additionally, in movements, there is a far stronger sense of the presence and active power of God delivering people. In traditional churches, the flavor of encounter is more of the “I suddenly understood what they’d been saying” variety; in movements its more “I had this terrible sickness or I was possessed and Jesus appeared to me in a dream and told me to go to these people and they prayed for me and I was healed.”
Second, people in traditional churches often think of discipleship as a kind of program, a long-term effort of the church, special training, etc. In movements, people join in discovery groups – but these are not really like “small groups” in the West in how we typically think of them. They are often an extended household or multiple households living nearby. Such small discovery groups truly walk life together – they continue for long periods of time through stages of life, so discipleship is ongoing. Together, they are reading Scriptures and actively seeking to apply them in their own lives. In this setting, discipleship never ends.
So, yes, movements do encourage rapid expansion – encouraging and empowering people to begin sharing their faith, even from the very beginning of it. Most movements encourage people to begin sharing stories of Christ with others the instant they hear them. But this doesn’t mean discipleship ends and sharing one’s faith. As people are walking with each other, they are encouraging each other through processes like sharing with others and forming new groups. On the ground, groups tend to stay together (except in cases of migration, etc) and coaching relationships develop between groups and leaders of groups.
This becomes a very stable ‘network’ of churches that are intensely walking through life together, worshipping together, obeying Scriptures together, and encouraging one another – a very intense and thriving structure. In this situation, discipleship and leadership training are not one-time–they are perpetual, and that changes a lot of measurements.