Thanks for bolding.
I'm not an expert, but I think it's apparent that the weaknesses we succumb to are defects ("faults") of our inherent created goodness that have been exploited by sin. In other words, a sin is rooted in a pervesion of a good. Example: anger is often rooted in a sense of justice that has been incorrectly understood and acted upon.
Knowing this is useful -- essential, I'd say -- to avoid the sin.
It definitely serves to help us know ourselves better, doesn’t it?