I think I would be right in saying that much “missional” theory these days accepts that in our post-Christendom and post-modern cultural context there is likely to be a significant transitional period between first serious exposure to the “gospel” and conversion. People don’t simply get saved. They set out on a journey. This seems to me to be true to the extent that, in many instances, we have to reckon with large numbers of people—communities almost in their own right—who are attracted to Christ, even to the life of the church, but who remain fundamentally uncommitted.
In the New Testament context these were the “God-fearers”—Gentiles who were drawn to the ethical monotheism of synagogue Judaism but for whom it was a step too far to become proselytes. We would probably call them “seekers”, and we get frustrated with them after a while because they never seem to want to find what they are looking for.