“Sin lies only in hurting others unnecessarily. All other "sins" are invented nonsense.”
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Robert A. Heinlein 557
American science fiction author 1907–1988Related quotes

Book II, ch. 3 (trans. Constance Garnett)
The Elder Zossima, speaking to a devout widow afraid of death
The Brothers Karamazov (1879–1880)
Context: If you are penitent, you love. And if you love you are of God. All things are atoned for, all things are saved by love. If I, a sinner even as you are, am tender with you and have pity on you, how much more will God have pity upon you. Love is such a priceless treasure that you can redeem the whole world by it, and cleanse not only your own sins but the sins of others.

Source: Life Together: The Classic Exploration of Christian Community

“All other sins are open,
Usura alone not understood.”
Addendum for C
Drafts and Fragments of Cantos CX-CXVII

“All piety consists therein
In them, in other men all sin…”
Canto I, line 189
Hudibras, Part I (1663–1664)
Context: For his Religion, it was fit
To match his learning and his wit;
'Twas Presbyterian true blue;
For he was of that stubborn crew
Of errant saints, whom all men grant
To be the true Church Militant;
Such as do build their faith upon
The holy text of pike and gun;
Decide all controversies by
Infallible artillery;
And prove their doctrine orthodox
By apostolic blows and knocks;
Call fire and sword and desolation,
A godly thorough reformation,
Which always must be carried on,
And still be doing, never done;
As if religion were intended
For nothing else but to be mended.
A sect, whose chief devotion lies
In odd perverse antipathies;
In falling out with that or this,
And finding somewhat still amiss;
More peevish, cross, and splenetick,
Than dog distract, or monkey sick.
That with more care keep holy-day
The wrong, than others the right way;
Compound for sins they are inclin'd to,
By damning those they have no mind to:
Still so perverse and opposite,
As if they worshipp'd God for spite.
The self-same thing they will abhor
One way, and long another for.
Free-will they one way disavow,
Another, nothing else allow:
All piety consists therein
In them, in other men all sin...

"Christ The Redeemer" in A Body of Divinity http://www.fivesolas.com/watson/redeemer.htm (1692).
“What harms no other is not sin.”
A saying in Cuzeian theism http://www.zompist.com/cuzeian.htm#Responsibility
Fictional sayings