Here is another thought on momentum from Andy Stanley, adding to the others I mentioned here and here.

I love my church. But right now, I think my pastor and most of us would agree, Anchor lacks momentum. We're nowhere close to being a dead, status quo, business-as-usual church, and lots of ministry still happens. But momentum? Not so much, right now.

When Anchor (my church) started over ten years ago, we definitely had momentum. But I'm not sure why. And I'm wondering if we did something to kill it. Did we make a "stupid decision" somewhere along the line? I can't think of anything offhand, but I'm gonna keep pondering. 

Can you point to a stupid decision your church made which, looking back, may account for your lack of momentum?