I'll repost something I said in a previous thread that dealt with a similar topic. It was about why believe in God if there's no evidence for his existence. The same logic can be applied here.
"Assuming there is no God and all the positive results people experience are just a placebo effect, why exactly is that a problem? If belief in God makes me a better person, isn't that enough for me to justify my belief? Why get rid of something that's beneficial for me just because of the perceived evidence? It would be like someone stopping medication that's clearly working for them just because some people believe the evidence says it shouldn't work. There's no proof on whether God exist or not so I believe its logical for me to choose the option that yields the best results."