“What matters is that you are sincere” sounds like good advise, and it is, as we shall see in a moment. But it can also be the worst advise to give anyone. God does, indeed, want us to be sincere about what we do. A common dictionary definition of sincere is “free from pretense or deceit; proceeding from genuine feelings”. It is wrong to be pretentious and deceitful. We must always strive to be genuine, honest, in other words, sincere. Integrity.
But what if being true to who we are involves doing something that is hurtful and unkind and unloving? What if I genuinely don’t care about the homeless and the sick? Should I be sincere even then? Would it be pretentious to “do” caring things to such people because that is “the right thing to do”? Such questions lead us to something that often goes un-examined when we talk about “being sincere”: It matters what we are being sincere about. In other words, our personal feelings are not the ultimate standard of what is right or wrong. We are not automatically doing right just because we are doing what we feel like doing. There seems to be a standard of right or wrong, outside of our feelings.