Which psalms to sing (Andrew's Question from earlier)

I’m indebted to Andrew for making this comment on another post. I’ve moved it here because I think it is worth discussing in its own right, rather than in the comments for something only tangentially related.

Andrew says:

Would it be possible to have a channel on which to write comments not specifically connected with the topic under discussion?
To give a concrete example, why do we sing psalms like the one we sang on Sunday morning? It speaks of spurning the company of “the wicked” and washing our hands of their affairs. This is emphatically not what Jesus did. Plenty of other psalms are less anti-Christian in their outlook.

I can’t remember precisely which psalm this was referring to, but I can say why we sing the psalms we do.

The psalms for the Sunday morning service are chosen as part of the Lectionary that we use. A Lectionary is a collection of suggested Bible Readings. The one we use is in wide use across the world. Generally on a Sunday, our neighbours in the Church of Scotland and the Roman Catholic Church will be reading similar readings to us. (Often they are exactly the same). The psalms which the Lectionary suggests are designed to be a response to the first reading. They are not set in order to make us feel good, but rather to allow us an insight into the emotions and characters of the first readings. Thus, if the first reading is about something terrible happening to someone (Joseph being thrown into a pit by his betraying brothers for example) then the Psalm can be expected to lean towards lamentation rather than praise.

Sometimes it can be just this kind of thing which touches people the most. Lots of people who come to church on a Sunday have their own troubles which can be mirrored in exactly this kind of psalm. Generally speaking, the hymnody that we use at St Mary’s tends towards the upbeat. I’m pleased about that, but also pleased that sometimes we weave into that strain of praise other expressions of the human condition.