22 But the fruit of the Spirit is love, joy, peace, longsuffering, kindness, goodness, faithfulness, 23 gentleness, self-control. […]
In Gal 5:22 πίστις (G4102) – “pistis”, or faith (you can call it “faithfulness” as long as you understand that it’s the same exact word that’s translated “faith” just about everywhere else) is listed as the fruit of the spirit. So is love, joy, peace, etc. All those things are what my spirit produces as fruit. Meaning the Christ-kind-of faith faculty is there, and if exercised correctly, is able to produce in no worse a way that the faith of Christ himself produced when he walked on this Earth.
Animals don’t have faith faculties like humans do. God didn’t give them any. Humans do, because God endowed us with such. However, God won’t exercise our abilities for us, we have to do that part.
Muscles are a gift from God. (in a sense that God created 2 prototypes – Adam and Eve – with a complete set of muscles, and they have been reproducing that faithfully since). A well-developed musculature, on the other hand, is what you do with that gift. No one was born looking like Arnold Schwarzenegger. You have to develop your muscles.
Ability to believe is by all means a gift from God, in that sense. How I use that ability, however, is up to me. (However, when I do use it, I expect it to work, since it was designed by God, after all!).