It’s not who you believe in that determines the quality of your life but what you believe in. The various religions share common morals. The Deities and stories are different but at the core many are the same. Staying true to those universally accepted morals and your own sense of right and wrong will bring you happiness in life.
If you were to find out that God didn’t exist would you regret being in your religion? If my belief system concerning God were proven wrong I wouldn’t have regretted anything because my belief in God has not caused me to do anything I don’t want to do. Everything I am doing now I would do whether or not there is a God.