We are such entities and we live in such a world that we will do wrong, over and again, in small things and in large.Life is a process of trail and error - and it very much looks as if that may be part of the point of being alive as earthly, incarnate mortals.
So, doing the wrong things cannot be regarded as fatal to human purpose.
But, but, but - on the many, many occasions that we err, we have to acknowledge error; we must acknowledge that when we do wrong we have done wrong.
We must not (must not) get into a habit of self-justification.
A rooted and inflexible attitude of self-justification is the basis of some of the morally-worst behaviour I have seen in men and women.
In men self-justification comes out at the Right Man, the man who is always right about Everything, who never acknowledges ignorance or error or bad motivations in himself - the man who is always been 'in the right' in every situation of his life. The man who believes that If Only everybody had always listened to him and always done what he said, then the world would be a much much better place.
The Right Man acts as if it would be a world-ending catastrophe is ever he admitted error; as if the two possibilities are to be a person who is always right about everything or always wrong about everything.
In women self-justification typically comes out as the Victim, the woman who is always being slighted - either deliberately or casually; offensively patronised or subject to negative discrimination; ignored or picked-on; treated as 'just a woman' or treated 'as if she was a man'.
The Victim acts as if it would be a world-ending catastrophe if she were not the centre of attention in all situations and at all times, yet she finds intolerable the psychological pressure of being the centre of attention - because then people always expect something of her.
Both the Right Man and the Victim are characteristic modern types, and both are encourages by mainstream modern culture as expressed in the Mass Media - which embodies the attitudes and evaluations of the Right Man and the Victim.
But if self-justification is something is a common evil - then its opposite is (of course!) also an evil: the inability to hold to any principle, because of unclarity, unsureness, uncertainty; the evils of nihilism and despair.