Why do people pray when they could do something actually useful?

It angers me when religious people say "I pray for the sick, weary, unfortunate" and so on but do NOTHING that would actually help them like look for a cure for their disease or fund a relief effort. It seems like their prayers do nothing at all but alleviate their own guilty consciences, if we had all relied on prayer alone medical science would still be barbarity and technology would have remained at the level of chucking stones. And NO I'm not exempt from my own accusations I feel ashamed of my lack of effort, good people die while the rest are busy "praying" for them!! What a joke!