I think sometimes we neglect to notice just how much the Church has been influenced by evolutionary ideas (and my scientist friends would yell and complain about this - but I am speak of it in popular terms and understanding). As Western culture moved into the 20th Century, there was a wave of positive hope and expectation - we are improving, we are "evolving" - things will get better and better.
This idea has impacted the Church. Think of the popular expectations. That we will always grow - if your Church isn't bigger (and better, that's assumed too), then there is something wrong and we need to do something different to meet those expectations. The assumption is that the Church normally grows.
The only thing is - that's not what we see in Scripture. We don't see constant growth - we see a falling away and a restoration - we see the people wander off while only a remnant remains.
That is a dirty word to many folks - a remnant. A remainder - but a portion of what once was. But, that is what happens and has happened over the course of history. Popular Cultures are appealing, and people fall away. Preachers give into popular demands. Churches fall away en toto.
Does that not describe what we see happening today? Would not even the most liberal among us in the Missouri Synod admit that culture is becoming far more open and indifferent to traditional morality (now, they might not agree that this is a bad thing, but still, it's happening)? As such, if we remain faithful, we will stand out more and more, we will appeal less and less to general public, for we cannot offer what the world does, and even the illusion of doing so will fade away (no more folks joining the Church to keep up appearances, when that appearance no longer matters).
This is the way things work. I think it may be a time like that into which we are entering. I hope it's not. No one is who in it likes it when it is that way (Elijah certainly didn't). But I see it within my own congregation - a small, graying Church in a shrinking rural town. 50 is much more likely than 150. And 10 years down the line - who knows then.
But perhaps we just need to change our perspective and abandon those ideas of expected growth that we cling to. Maybe our focus should be on being faithful, of preaching Christ and Him Crucified, in season and. . . as it looks to be. . . out of season as well. And then let the chips fall where they may.