The sin which is unpardonable is knowingly and wilfully to reject truth, to fear knowledge lest that knowledge pander not to thy prejudices.

If pride is a sin ... moral pride is the greatest sin.

The unpardonable sin, in Campbell’s book, was the sin of inadvertence, of not being alert, not quite awake.

Indifference is one of the seven deadly sins, actually the greatest
of them all, because it is the only one that sins against life.

To remain silent and indifferent is the greatest sin of all.

The Seven Social Sins are:

Wealth without work.
Pleasure without conscience.
Knowledge without character.
Commerce without morality.
Science without humanity.
Worship without sacrifice.
Politics without principle.

From a sermon given by Frederick Lewis Donaldson in Westminster Abbey, London, on March 20, 1925.

To wish to withstand the Holy Spirit would be the one unforgivable sin.

The biggest sin in Satanism is not murder, nor is it kindness. It is stupidity.

The worst sin towards our fellow creatures is not to hate them, but to be indifferent to them. That's the essence of inhumanity.

While injustice is the worst of sins, despair is the most dangerous; because when you are in despair you care neither about yourself nor about others.

Now listen to me, Buddy: there is only one unpardonable sin - deliberate cruelty. All else can be forgiven. That, never.

For it is beyond doubt that there is nothing which more shocks our reason than to say that the sin of the first man has rendered guilty those, who, being so removed from this source, seem incapable of participation in it. This transmission does not only seem to us impossible, it seems also very unjust. For what is more contrary to the rules of our miserable justice than to damn eternally an infant incapable of will, for a sin wherein he seems to have so little a share, that it was committed six thousand years before he was in existence? Certainly nothing offends us more rudely than this doctrine; and yet, without this mystery, the most incomprehensible of all, we are incomprehensible to ourselves. The knot of our condition takes its twists and turns in this abyss, so that man is more inconceivable without this mystery than this mystery is inconceivable to man.

Krishna says in the Gita, “The worst crime in the world is indecision.

nothing is so displeasing to God as an impenitent heart. Impenitence is the one sin for which there is no forgiveness.