As is the case with many word which in times past would drip with meaning and relevance, 'inspire' is used and abused at almost every turn. Both the OED¹https://beingreasonable.com/definitions/#inspireoed and Webster's²https://beingreasonable.com/definitions/#inspirewebsters inform us that 'inspire' has spiritual overtones. The OED, being a diachronic dictionary, goes a bit deeper and points to the earliest figurative use of the word to be specifically Christian in nature.

Inspire

The etymology for 'inpsire' given by the OED tells us that it is an "adaptation of Latin inspīrāre to blow or breathe into, from in- + spīrāre to breathe." Analogously, Webster's states that it is "from Latin inspirare, from in- + spirare to breathe" and that for further information, we should see "more at SPIRIT." Hence...

Spirit

The OED is rather verbose in its etymological accounting for 'spirit,' informing us that it is "adapted from Latin spīritus breathing, breath, air, etc. related to spīrāre to breathe." It delves even deeper, telling us that the "earlier English uses of the word are mainly derived from passages in the Vulgate, in which spiritus is employed to render Greek πνεῦµα and Hebrew rūaḥ. The translation of these words by spirit (or one of its variant forms) is common to all versions of the Bible from Wyclif onwards."

Webster's is less verbose, but tells us essentially the same thing at core: "from Latin spiritus spirit, breath; ... Latin spirare to breathe"

The salient fact to be aware of here is that these terms both derive their force, power, and essence from the Holy Bible, as is the case with most of the important words in the English language.

Putting It Together

spirare is the present active infinitive for spiro.

spiritus is an etymological derivation of spiro.

Finally, per what we were informed of in the above, spiritus in turn was used in the Vulgate to translate the Greek πνεῦµα, which in the BDAG³A Greek-English Lexicon of the New Testament and Other Early Christian Literature, 3rd Edition, s.v. "πνεῦµα." is, most importantly, identified with "God’s being as controlling influence, with focus on association with humans, Spirit, spirit as that which differentiates God from everything that is not God, as the divine power that produces all divine existence, as the divine element in which all divine life is carried on, as the bearer of every application of the divine will. All those who belong to God possess or receive this spirit and hence have a share in God’s life. This spirit also serves to distinguish Christians from all unbelievers," in other words, the Holy Spirit.

It would therefore be reasonable to conclude and hope that a story described as being 'inspiring' would be such that it would be infused and suffused with that which is holy, i.e. with that which is inestimable, ineffable, and incorruptible.