I don't think any major religion defines "being rude" as a sin.
That's the whole point. Even the smallest failures to live perfectly disturb the world. In ways we often can not predict or know.
I said I was not perfect. I do not consider myself a sinner.
To simply justify oneself by claiming all one's actions are insubstantial or "justified" is self-serving.
You generally agreed with me on substantial and justified. Where am I being self-serving.
Of course they do. Treating people unkindly is sinful. Do unto others, etc.
I said I was not perfect. I do not consider myself a sinner.
Yeah, I get that. I am saying that your definition of sin to only include "substantial" and "unjustified" things is wrong. If you are not perfect, then you have sinned.
It's really that simple.
You generally agreed with me on substantial and justified. Where am I being self-serving.
You are being self-serving in thinking everything you do is either justified or insubstantial in terms of the harm you introduce into the world.
When you accept anything less than perfection as a goal to live up to, you invite rationalization of one's own defects into the "insubstantial" category.
SD