I suppose you say that ironically, if I know you a little. Actually, if done in all honesty and complete devotion, it will bring that result (to begin with by suppressing many deleterious passions: resentment, envy, jealousy, selfishness, covetousness etc.).
Belief in God is not just for your physical or mental health; it's acknowledging that an all-powerful being exists - but it exists whether you believe it or not.
Someone once said that it takes more faith to be atheist than to be a believer. Having seen how people act in regards to their beliefs, I find this to be true.
However, according to a certain American tradition (pragmatism), if faith is effective, It gives results, is good for you, keeps you healthy, then it is true.
Doc, If you only knew how many people are self-deceived! One sees, wants, believes not what actually (objectively) is, but what gives us pleasure, what satisfies our ego.
Complex issue. We are not fully conscious of everything that goes through our minds. There are conscious, preconscious and unconscious elements with strong emotional value (with roots in childhood) that affect us in spite of ourselves, and which we cannot control or suppress.