While in theory most missionaries acknowledge that if all goes well the time will come that they will no longer be needed on the field where they have invested their lives. In practice it's not so easy. It's hard to recognize and accept that we aren't need, much less to admit that our continued presence could actually be a detriment to the work.
In an article on the Southern Baptist missions website entitled, "The Missionary Task: Working Yourself out of a Job", D. Ray Davis described the situation as follows:
. . . precious resources and years of missionary effort can be wasted if exit is handled improperly. Premature exit puts the new work in danger of an early demise, but prolonged presence can also foster dependency. Discerning when to exit requires wisdom, prayer, and dependence upon the Holy Spirit.
If a church is healthy and capable of replicating, then continued involvement by missionaries can prevent that church from standing on its own. That is, exiting too late hinders healthy completion of the missionary task. On the other hand, exiting too early undermines the overall missionary task.
A tremendous benefit of healthy exit is that when healthy churches are planted, missionaries have the freedom to move on from one mission field and work in another context. By “healthy,” we mean that the church faithfully bears the twelve characteristics of a healthy church. It’s also a church that is self-led and self-financed.
Healthy, furthermore, means its people are aggressively sharing the gospel and planting new churches. Healthy further denotes they are fully able to train their own leaders well and have joined the global body of Christ in taking the gospel to the ends of the earth.
Effective exit and ongoing partnership are enhanced through long-term partnership with US church partners. Partnership between field churches and US churches provides a mutual training ground where both are strengthened. . . .
We do not lose our commitment to walk alongside churches we have planted simply because our full-time presence is no longer needed. Rather, we enter into a new phase of partnership with these churches as, together, we press on to complete the Great Commission.
One wonders how well we as GP have thought through and implemented exit strategies for our fields. Or could it be that often we exited simply when we had no one else to send whether or not the field was ready? One also wonders how often we've left behind an "unhealthy" church, not because we left too soon but rather because we stayed too long? How well are we doing with this on our Phase 4/5 fields right now?