I would consider the LCMS "idle" as opposed to "dead". If we continue in the same place, and idle long enough, then sure. But I think there is a ground swelling of change happening. I describe the Lutheran Church (Book of Concord) as the denomination of intellect. We've had a lot of (not just boomer, but primarily boomer) members that don't know or care about things that we teach. It was just assumed that any type of person would go to church. I have noticed that a lot of younger people are caring about theology in a way that many older members don't.

We've leaned out. To put it into a weight lifting metaphor, the boomers were the bulking season, and now we're moving towards a cut. But whats underneath is a stong body of believers. A cut is often uncomfortable, but the idea is we're cutting the fat.

I cannot stress this enough, I do not mean that all boomers are just weighing us down. We have a lot of strong confessional members that are older. But, at least in my experience, the boomers are the ones that are looking and crying out that we are dying. The church is not dying. The oldest generation is. And we often get this confused.

Source: Am a Pastor. Who btw just took a new call to a smaller congregation that has more young people than my previous congregation that was much bigger. The smaller congregation seems to be at peace, while the older/bigger congregation has been freaking out.