i agree but when you are a Christian and Hear it Sunday after sunday...the "Baby" christians start to wonder is that all there is? and the older Christians get board and want to know more but have trouble understanding areas and start asking question and get pointed back to where they started.
Most churches (if they pay attention) seem to get the idea that there are 2 parts to being a good church.
1. Spreading the word to the lost
2. Nurturing and supporting the flock
Those that are lost
need the story of Jesus' sacrifice and birth- the fact that He was willing to give up His glory to become one of us, just so He could relate to us and eventually be our Salvation. (And every now and again I know I need to be reminded of it again, too!)
But then you are right, every Sunday should not be about that. Because growing Christians need to learn more. We need more "in depth" stuff. We need to learn about Jesus' every day life to strive to become like Him (or as close as possible.)
But on the other hand, it is our repsonsibility to seek this out, too. We can come together in Bible studies, go to seminars, look online (like here <img src="/images/graemlins/grin.gif" alt="" />), etc. Part of maturing in Christ is knowing that we need to know more and taking the responsibility for finding it out for oursleves. To go back to the baby illustration: we can't be spoonfed forever. But for the un-saved, they often don't go looking so it is up to us to bring it to them - or at least offer it.