“We hear it frequently remarked that it matters not what one believes if he does right. But if one does not believe right, he does not do the right thing—that is, if his belief is sincere and carried out in practice. If one believes that which is wrong, and still acts otherwise from force of circumstance, he is wrong in heart. A man may believe in polygamy, but the law and common custom may forbid its practice. He would be in outward life aright, but in heart would be a virtual polygamist. And if circumstances were favorable, his life would bear its legitimate fruit. And this is just as true of every other moral evil. It is all-important to believe right. Every false religion which has cursed mankind has started in a wrong belief. It might not have affected practical duties for a time, but the fruit finally developed. Thus belief in that first lie of Satan’s (Gen. iii: 4) has borne its legitimate fruit in—first, the deification of the beautiful, and unnatural curiosity; second, self-love, delusion, and idol-worship; third, free-thinking, protesting, infidelity, and anarchy.”

+ St. Sebastian Dabovich, The Lives of Saints: With Several Lectures and Sermons [hard-copy book] | [read online], “Sincere Religion”