You couldn't be more wrong. In fact, once a person is dead, there is no point in praying for them. Its too late at that point.
Maybe it's just me, but I've always been of the opinion that there is room for both - Prayer alone will never do anything - a combination or Prayer AND Action, on the other hand, is what is necessary.
Personally, I think God also feels that way - He doesn't want to do everything for us. He wants us to help ourselves (Free Will), too, and if we at least try by taking action in combination with prayer, he may decide to give you a hand :0)
But, I'm a cynic ;0)