If studies have shown that religious people are more likely to be charitable than non-religious people, I pose the following scenario, and ask your opinion:

Let's say I'm a dog lover and I want to raise money for the local animal shelter. I go door to door in my neighborhood with an empty coffee can, asking for donations. However, instead of telling people what the donations are really for, I tell them that they're for a local 12 year-old girl whose parents were killed, and who lost both her legs in a tragic car accident.

The net outcome is good, but I'm misrepresenting the facts and convincing people to believe something that isn't true.

If one of the arguments for justifying religious belief is that it makes people more charitable, and also makes them feel good, even if there's not really good evidence or justification for it, wouldn't that justify a whole slew of scenarios like the one outlined above? If the end result (happiness, charity) is more important than truth, are we not justified in misrepresenting facts in order to make people happier and more charitable?