Let's look at the first truth about longevity: trust. Mark DeVries, in his book Sustainable Youth Ministry, mentions this idea. To earn the trust of your students, parents and lead pastor will depend on how long you have been in your position. Now, of course, you can lose that trust over time as well. So, be wise with your decisions.
The second truth "freedom" to change things is also tied to longevity and a proven track record. If you simply change things for change's sake, you might lose some credibility. However, if you have proven yourself over time, and you take the right amount of time to make a change, most people will follow. We are in that process now. We are spending about 6-8 weeks asking the students and my adult leaders to pray and think about this question: "What future for Veritas requires God's power?" After we get a sense of what this might be, we will take it to the leaders of the church, and to the parents for their affirmation.
The third truth about longevity is influence. Again, this is also tied to your character and judgement. The longer you stay in one place, the more opportunities there are to lead. The more people begin to know who you are and that they can trust you, you earn the right to be heard and have influence. Gone are the days of influence and respect because of some title given to you. With this current generation, influence and trust is earned.
In my opinion, the longer you stay in your current ministry position, the more trust you can earn from students, family and pastor, gain more freedom to change and lead, and the more influence you will have. My prayer for you is that you will consider the impact of staying.