The need for a consistent and sustaining devotional life. Perhaps it is a particularly American trait that we seek spiritual independence - not only from other Christians, but from God Himself. But the message of Romans 7 and 8 is precisely that we cannot do it alone, even as newborn saints. When Jesus returned from the Mount of Transfiguration to find his disciples helpless before a demon, He told them their problem was a lack of faith. Prayer is probably the most difficult area of the Christian life for the vast majority of us.
Missionaries are no exception.
By doing surveys and keeping careful records some mission agencies have discovered, for example, the vast majority of young African animists that come to the city to study will convert to either Christian or Islam within the first year. Missions are using such information to allocate their resources to the ministries most likely to produce results. The development of these tools is one of the most significant events in the fulfilling of the great commission for our generation. I am really excited about these technical advances, but I do think that we need to remind ourselves that just as sharper tools demand a better craftsman, improved methods demand purer motives. As we seek better technical training, we must not forget the crying need in missions today is for spiritual men.