Hasn't really shown anything like that. He isn't a wizard which Jim said the Saints are wizards.
Wizards or sorcereres, which opens up a substantially larger pool of lesser teir talents. That being said I do not think Father Forthill has any "Magic" beyond his being a Holy man that can sense the Soul, etc. Mostly because he'd be using it if he could, he's well entrenched in the factions of the Church that would have the knowledge and resources to train him in a religion school of magic.
The inevitable question here is, is Saint equal to Practitioner, or Wizard? Cause what about say, Charity praying and using magic by incidence more than design, Or Tilly Wishing a guy would just confess to a horrid crime maybe?
Jim said " a wizard's
or sorcerer's talents". This makes me think Saint is not about relative Power level or breadth of knowledge, it's more about the "blended faith magic with their natural abilities" part to accomplish some amazing things. So there can likely be a pretty broad base of people, some Faith-sorcerers who have a single trick (Lay On Hand or something?) and others that are more studious and so have the knowledge to apply it more broadly. Purely summoning Faith energy into a religious artifact would not itself count if only because that would make literally every wiccan with a shrine in her home one, making most of the Ordo Saints by default, not to mention Susan back in GP when she barely believed. I'd place it somewhere around the same line as people with misc magic quirks and talents vs somebody that has learned to harness sorcerer levels. If the Alpha's were religious, they might be the bottom rung with a single faith-Trick. There'd still have to be the hack-level users like Thomas describes himself with magic. For a Saint I think you have to actually straddle the line more, you have to have BOTH a strong faith and reasonably strong magic, and you have to have learned in a school/environment that specifically blended the two as I expect was far more common back in the day with shamanistic practices, competing polytheistic temples, etc.
The only thing i recall of Harry and faith is his commentary in Grave Peril.
There's one in Storm Front when he first met Bianca:
Second, he'd passed me on with my pentacle still upon my neck. He probably figured that since it wasn't a crucifix or a cross, that I couldn't use it to keep Bianca away from me.
Which wasn't true. Vampires (and other such creatures) don't respond to symbols as such. They respond to the power that accompanies an act of faith. I couldn't ward off a vampire mosquito with my faith in the Almighty-He and I have just never seemed to connect. But the pentacle was a symbol of magic itself, and I had plenty of faith in that.
[...]
The pentacle began to burn with the cold, clear light of applied will and belief-my faith, if you will, that it could turn such a monster aside.