Rate and depth of change have so much to do with the life cycle of the church that it is hard for me to make a broad generalization. Let me toss out two churches on our district as opposite examples.
I came to my church 3 1/2 years ago. The church had been in strong decline for nearly a decade. The previous 20 years had seen very strong growth under a great leader. (from 120 range to a little over 400) The reason the church grew under this man was that he was an extraordinary pastor. He knew everyone's name, their kids names and often their birthdays. (Think about this in a church of 400) He worked a cazillion hours, did all the pastoral care and on and on. He died of a stress related heart condition while pastoring. People loved this man and his love and care for them overcame the fact that he was very traditional in his music, unfortunately his style of leadership was not sustainable and it ultimately killed him. This left a very traditional church with a Hymn service and choir in the midst of a Seattle suburb community that was exploding with young families. Fast forward 10 years and all the young families are gone. The youngest people of any number are in their 50s and are threatening to leave. The church is down 40% and the demographic has completely changed. The new folks that have come are refugees from all the other churches that have gone contemporary. I was brought in "to reach young families." The problem is - They are doing a really great 1985 service and it is 2008. The sudden movement from 1985 to a contemporary service could not have been done slowly and it was painful.
Another church on our district just a few years ago had it's pastor of 30 years die while still serving the church. That pastor, rather than getting frozen in time had for 30 years constantly introduced small progressive changes. I was in worship with them 3 weeks ago and they do a contemporary service. There are lots of blue hairs and young families. Everyone loves the music. There is great unity in this church and it grew, under the previous pastor from the 120 range to the middle 500's.
Here is the problem. If churches will be constantly adapting they can avoid much pain. Unfortunately many, many churches choose to "freeze" time in a place that the folks in power like. This works for awhile and creates great joy for that demographic. Unfortunately they will eventually have to pay the price. -
In my opinion, not all churches are the same. There is no one way of doing it. It depends on the situation. The first question I would ask is, what is the long term growth curve of the church relative to the growth curve of the community. That will tell you a a lot about the health of the church.
Of course the third option is that we allow some churches a sort of death with dignity. Which I think is a real choice. We just need to be honest about it.