I spent 9 years in full-time youth ministry at the same local. At that time the drop-out rate among youth ministers was somewhere around 2 years and 60% of those never return to any form of paid ministry.
For me, my call had changed, and the things that God had put on my heart no longer applied to just youth. It took me and the church that I pastored some time to realized this reality...so, my job description changed.
From a biblical perspective, the Apostles often spent less time than 2 years at a local. The difference is that they continued to encourage the people through letters and sending others people in their stead (Paul and Timothy for example). Secondly, the Apostles raised up and appointed elders to continue to watch over (not directly do) the ministry after the apostles left.
Honestly, I always wrestled with how the body of Christ got broken up into little segments with individual pastors (in respect to generations or people groups with a body). I'm still not sure how I feel about the whole thing today.
I do disagree with how the process of "selecting" or "calling" takes place. Typically, a church sees a need, defines the need with a job description, then finds someone to fill the slot. The person who then fills the spot must then work within, fill, and is evaluated by the job description. Often the job description is so specific that it hamstrings those working within it to fully be who God has called them to be. In some sense, the job description becomes their God. Ministers who want to be faithful to God and the people are caught between a rock and hard place. In the best environments the minister and the people recognize this and can alter the job description and allow the minister to change his role as he/she is moved by the Holy Spirit. In the worst case, the minister must leave in order to be what God intends.
I think a more scriptural understanding is that of "recognizing" or "awareness". This requires prophetic/spiritual sensitivity. We see this when Paul was sent forth.
Acts 13:1-3 - In the church at Antioch there were prophets and teachers: Barnabas, Simeon called Niger, Lucius of Cyrene, Manaen (who had been brought up with Herod the tetrarch) and Saul. While they were worshiping the Lord and fasting, the Holy Spirit said, "Set apart for me Barnabas and Saul for the work to which I have called them." So after they had fasted and prayed, they placed their hands on them and sent them off.
(from New International Version)
I find it interesting that the phrase "...to which I have called them" is used (past tense). This call wasn't news to Paul. I think he had been aware of his call. The prophets and teachers spiritually discerned the call of Paul and Barnabas and sent them forth. Here a "position" was made because of call rather than a call made because of a position. In scripture we see people being appointed (elders, judges, people full of the Holy Spirit to distribute food) and recognized. Most of the time the appointing is accompanied by recognition.
The process of helping people discover and discern their call, mature in their call, take responsibility for their own call, and recognize and release them into their call is an unheard of process in the modern American church. Typically churches are trying to create spots to be filled rather than recognized peoples call and create positions for them. If you have someone in your midst who is gifted at teaching he should be called a "teacher" and allowed to teach. If some one calls himself an "Apostle" but has no apostolic skills he should be called into question. BTW, one of the roles of the the New Testament prophet is to recognize and validate the call of God on others.
When churches become focused on filling spots they often then neglect the call of "recognition" and those who have a genuine call from God are neglected. Another issue is those who have a call and refuse to take the full responsibility for it and expect others to make it a reality for them. Both of these have the end result of disillusionment for all persons involved.
So in respect to youth ministry, many leave because they change. Many leave because youth ministers get paid some pretty trashy wages. Other leave because they are not allowed to be what God intends them to be. Others leave because they got the training but didn't have a call.
In the end a true call from God must be recognized and responsibility taken for the call. If there is no spiritually discerned call something isn't going to work.
Adam
The American dream and the Dream of God are not even on the same map.