Let us consider those sins that some people call ‘lesser’ and which are not, of course, mortal, but still bear a certain weight of guilt. We sometimes fall into these through inattention or ignorance, sometimes through languor and weakness of will, and, on other occasions deliberately, with our full knowledge and will. The greater weight of guilt belongs to the last category.
A sin can be considered lesser when we compare it to a mortal one. But it’s not to be taken lightly when we see it in isolation and for itself. For example, a lake may be called small in comparison to a vast expanse of sea. But it’s not small in itself, since it contains a great deal of water. In the same way, a lesser sin seems small in comparison with a mortal one.
But, in itself, it’s still a great evil. Since a small and a great sin are both equally transgressions against the divine law, as Saint John the Evangelist says: ‘Everyone who commits a sin, commits lawlessness also; sin is lawlessness’ (I Jn., 3,4). According to Saint James, the Brother of our Lord, if someone observes the whole of the law and errs in only one thing, then they’re breaking the whole of the law. ‘For whoever keeps the whole law and yet stumbles at just one point is guilty of breaking all of it’ (James 2, 10).
“Saint Nicodemus the Hagiorite”