Sincerity may be satisfaction and necessary for the possessors of that sincerity, but that your sincerity in your belief must be accepted by me as proof that I should believe as you do, is, I believe, the place where I have the undoubted right to say, "I reserve the right to my own conclusions and I am unjust to myself if I force myself to accept your viewpoint without full belief myself that you are right."
So, then, because a person is sincere in a belief that is contrary to your conscientious belief, do not be disturbed or swerved from common sense analysis or convinced against your better judgment.
No one possesses all the truth. It is for you and me to do our plain duty as we see it, to do the best we can each day in act and thought and word.
We can pretty much agree on the simple essential truths which are proven. That is, being honest, truthful, kind, lovable, sympathetic, cheerful, doing good, helping one another and doing things worth while.
If we agree on these things and do useful work and think helpful thoughts, we are doing our duty.
Theories, arguments and studying too deeply on bootless systems, codes, beliefs, cults, isms, or doctrines, is a waste of time.
When we can here and now derive definite benefits from doing the simple and helpful things and acting and thinking the simple practical cheer thoughts, it is not necessary or good for us to waste time on spiritualism or theoretical beliefs that cannot be proved to our own selves satisfactorily.
We are asked to believe these strange, impractical, unnatural beliefs, because of the sincerity of others. It's better to do, and to be the thing we can ourselves measure, understand and sincerely believe.
There are hundreds of strange beliefs and spiritual systems, each claiming to be all powerful, all right. If any one is all truth then all the others are all wrong.
The bigot who assumes he is the sole possessor of truth, the cult, sect, ism, or science that claims to possess all truth, and the exact rules for the world to obey, should be classed with those other misguided men and religions which burned human beings who dared to doubt their right to the possession of all truth.