Sin is infinitely hateful

"As sin in its own nature is infinitely hateful, so in its natural tendency it is infinitely dreadful. It is the tendency of all sin, eternally to undo the soul. Every sin naturally carried hell in it! Therefore, all sin ought to be treated by us as we would treat a thing that is infinitely terrible. If any one sin, yea, the least sin, does not necessarily bring eternal ruin with it, this is owing to nothing but the free grace and mercy of God to us, and not to the nature and tendency of sin itself."

From Temptation and Deliverance, by Jonathan Edwards. (In Works, Volume 2)