Twitter has displayed spiritual tendencies recently, with #prayforboston, #prayforiran and #prayfortexas all trending at one time or another. This is a fairly typical pattern after shocking events, but the exact function of praying for victims, and whether it is worthwhile, is unclear.
The ostensible answer is that prayer is a request to a God (typically omnipotent, omniscient and loving) to intervene through supernatural methods and aid the victims themselves. If a situation is ongoing, as the current disaster in West Texas is at time of writing, then God might be requested to calm fires, heal wounds, ease trauma etc.
Ignoring the obvious response that a God who did nothing to prevent the disaster in the first place would be unlikely to help with the aftermath, the problem is that intercessory prayer of this sort has not been conclusively shown to work consistently.
I stress the word "consistently" here: there are those who maintain that it still works sometimes, and scientific studies on the efficacy of prayer are often hampered by unknowable people outside the study praying for groups being observed. But nobody would doubt that not all prayers are answered positively - not just childish prayers for gold-plated swimming pools but seemingly deserving requests for strength or the alleviation of suffering.
This presents a problem, because if God intervenes sometimes then we can ask why It doesn't intervene all the time. Which is to say that if you pray to God to help the victims of the Boston bombings and your prayers are answered, but someone else prays for the victims of a comparable disaster and is ignored, then God (or someone on God's PR team) needs to explain why heaven is picking favourites. This might take the form of a statement saying that God only helps those who are worthy of help in some relevant sense, but disasters in which the innocent are the victims seem to have ample supplies of worthy sufferers. If prayer works for victims, then it has to work all the time, or we will have grounds to question God's goodness.
A second answer would be to say that prayer is a request for God to help the victims' families, but this faces the same problem as the first. So too will any answer which references petitioning God to prevent future disasters - if God stops one then God should stop them all. A final attempt to maintain that prayer has some kind of effect on other people might be to suggest that concentrated 'thoughts and prayers' themselves can impact the world without supernatural aid - cutting out the heavenly middleman. But many who pray would not, I think, see it this way, and this smacks a little too much of psychic detectives and tarot cards.
Instead it seems as if the function of prayer involves the person who prays, which was Kierkegaard's opinion also. (This would obviously be true if God failed to exist; until now we have generously been assuming It does.) Prayer could be an observer's way of rationalising or coming to terms with brutal world events by thinking aloud, framing their thoughts as moral concerns and ordering their emotional responses.
As long as this doesn't include any denial of the facts or constitute a substitute for helping confront the problem e.g. with charitable donation, then it seems as if prayer has value. (Whether it would constitute a denial of the issues around God doing nothing to prevent the disaster is an issue I sadly don't have space to go into.)
But I still sense that those who pray will object that this model suggests prayer has no more value for victims than thinking nice thoughts. Similarly, sentences like "You should pray for the victims" would lose much of their authority if there were no effect on the victims at all. I would love to get your opinion on this - do you pray, would you want people to pray for you, is it a waste of time? Leave a comment or find me on Twitter.