John Starke writes about the place of lament in corporate worship.
… the Bible gives us several good reasons why lamenting should be a part of our normal Christian worship, even if we are not lamenting our own circumstances. In no particular order of importance, here are four such reasons.
- We sing songs of lament even when we are not lamenting in order to weep with those who are weeping.
We sing songs of lament even when we are not lamenting so that when seasons of mourning come, we know what songs to sing and what prayers to pray.
We sing songs of lament even when we are not lamenting because the New Testament calls us to.
We sing songs of lament even when we are not lamenting because maybe you should be lamenting more than you are.
Read the whole post at the Gospel Coalition.
mgpcpastor's blog 
Number 1 is really important – even though some people in the congregation might be in Super Happy Jesus Time Alleluia Praise The Lord, the average Sunday morning attendance has people in all sorts of stages and situations in life… not just those with hopes and joys, but all sorts of worries, fears and crises.