The fact that the same author knew other, alternative and logically incompatible etymologies for the same word (mors comes also from amarus, 'bitter', or from the name of the god of war Mars) did not devalue the lesson, since it was the spiritual meaning and not the philological accuracy which stood in the foreground.
The author's awareness of different etymologies for a word (like "mors" coming from "amarus", 'bitter', or the god Mars) did not diminish the importance of the lesson, because the focus was on the spiritual meaning rather than the linguistic accuracy.