Sin

All sin is evil, and no sin is a little sin.
But what is little and what is evil ?
Is little a little little or a little bit evil, a little away from right, or just that little ?
Is little at times necessary ?

Talking about necessary…
So what is a necessary sin, what makes it necessary, why is it necessary and whats there to justify that necessity?

If it’s a justifiable one, is it still a sin, or it’s an act right, but deemed to be sin-ish ?

Are there any right reasons given for committing this ‘ necessary ‘ sin, or it’s a false misleading belief ?
Are some sins so necessary to commit than to be righteous at the point of committing them ?