Can an ambiguous word mean different things to multiple authors?

Solution 1:

Can it? (Is it possible?) Certainly.

Should it? No; if the authors cannot agreed on what a particular word means (in the context of the book in question) then it should be rewritten in some way that they do agree on the meaning. To deliberately use an ambiguous word to conceal differences of opinion seems dishonest to me.

If one author feels the need to acknowledge God while the other dislikes the notion, they might consider writing individual short introductions.

Solution 2:

Interpretation happens on the part of the reader, not the author. And different readers will interpret things in different ways.

As for blessed, yes, it originally has a religious connotation (obviously), but I feel it is more and more losing that direct religious link. If someone sneezes, I will say bless you, and I am not religious at all.

Without any further reference to god, the sentence in your paper will be interpreted by readers as they see fit. So one reader may attribute your state of being blessed to the divinity of their choice, whereas others will read it as "you feel happy".