Mike Glenn is spot on:
I have a theory. Yes, I know. Everyone has a theory. Church is out of touch. Church is too this or too that, but I think all of these other theories are wrong. Here’' my theory.
I think a lot of people stop coming to church because we never ask them to do anything great. We never call them to a vision that will demand everything from them. We never tell them to sell everything they have and go follow Jesus. We never tell them to head to the far reaches of the world and carry their casket with them because we don’t expect them to come back. We never tell them to leave everything and everyone they love to go start a church in some third world inner city slum.
We simply ask them to come to church and sit quietly. We ask them to give their money, sing reverently, but sit quietly.
Most of us want more, not less, from our faith, and if church can' help us get there, we'll get that "more we need" from somewhere else.
No one wants to come to church and sit.
Why would they? It's just more comfortable sitting at home.
Mike's entire post can be read here.