I think most churches do youth ministry because they think good churches have youth groups, or because they want to have something to offer parents who might come along on Sunday with their teenagers. Or they want to get their teenagers out of the way and get on with real ministry and real mission (by real mission I mean the stuff that happens overseas and doesn't threaten our comfort zones at all!)...

It is a rare church that does Youth Ministry because it believes it is the number 1 most effective way to see people grow into life-long Christians. It is even rarer that a church gives a Youth Ministry the first priority, most money and a well trained and paid staff member. It is a rare that a church recognises that Youth Ministry is usually the number one most effective mission field (even better than that remote random and nonthreatening unspecified location somewhere in the middle east).

But youth ministry should get top priority according to this blog post from the guys at Purpose Driven Youth Ministry.

I agree...