Providence tries to invoke the feelings of "Coincidence is on my side" and "subtle put powerful". It's also meant to work alongside the Righteousness and Holy Touch powers, letting you spend Fate Points on things that you really want to spend them on, rather than things you have to spend them on in order to get the most out of your powers.
Providence -X
Description:
Your choices and beliefs have a profound impact, granting you favor above and beyond simple chance.
Musts: The character must have taken Righteousness and Holy Touch.
Skills affected: Varies
Effects:
The world abides the believer
Belief has a powerful effect on the world. For every 2 points of refresh spent on this power, you may gain 1 free expenditure of a Fate Point per scene.
This feels like it would become a simple mathematical exercise in order to find the sweet spot for the power to get the maximum usage out of it. I don't like powers like that very much, and it doesn't feel like it would accomplish what you've set out to do.
The "coincidence is on my side" thing seems to be part of "guide my hand" rather than righteousness or holy touch. Especially when it comes to "faith manages". In that regard, it feels like you are looking for the faith powers version of refinement.
So I think I would do something like this:
Providence [-1]
Description:Your choices and beliefs have a profound impact, granting you favor above and beyond simple chance.
Musts: The character must have taken Guide my Hand and Holy Touch
Skills affected: Conviction
Effects:Faith moves Mountains: Your faith is strong. When taking this power, you either get 2 free uses of "Faith Manages" or you may increase your Conviction by 1 when rolling for "Faith Manages". You may take this power multiple times, but the bonus to your Conviction may not exceed your original rating.
You could extend the free uses to "Guide my Hand" as a whole, so you could use the fortuitous arrival part more often as well. I would say the uses should replenish similar to enchanted items.
Walking my chosen path -1
Focusing on your goal, you find it a much easier road to walk. Whenever you make a roll that is affected by Righteousness, you may make an additional roll to place a Conviction aspect on the scene that is somehow related to what you are doing to be used on your next turn.
Not a fan of additional rolls. And another thing that I think is an important part of the true believer: choice. You even got that in the name of this power. My suggestion:
Walking my chosen path -1
When your Righteousness would allow your conviction to complement a roll, you may forgo the bonus. If your roll still succeeds, you may place a fragile aspect on yourself, reflecting the power of your faith.
This would mean that you have to make the choice to not take a bonus now and risk failure, but you'd end up doubling your bonus when you succeed.
Grace Against the Dark likewise tries to invoke the feeling of "subtle but powerful" but with a much greater focus on "works best against the supernatural". It's intentionally very powerful, but completely useless against regular mortals.
Grace Against the Dark [-5]
Description:
Mortals who leave the safety of their homes may find themselves buoyed by the knowledge that a strong spirit can make all the difference when facing the unknown terrors of the world.
Musts: You must have taken Righteousness and Holy Touch.
Skills affected: Varies
Effects:
The Darkness Yields
Though the workings of the wicked may conspire against you, your faith will see you through. When faced with supernatural forces opposing your path chosen by Righteousness, you may add half your Conviction (round down) to your dice rolls.
Hmm...
A faith type character will likely have a conviction of 4-5 in most games, which would translate to a constant +2. +3 in any game that has unlocked the +6 skill level. 5 refresh is pretty expensive, but a constant +2 is enormously powerful as well. I would almost say gamebreakingly so. And it doesn't feel too subtle, to be honest.
And from a GMs perspective, if a player character has a constant +2 to everything he does, I would start to throw out opponents that are simply 2 steps better than what I would usually use, giving us a net result of +-0 for 5 refresh, which doesn't feel like a very good investment.
So I think I would go for more specialized things. For example the possibility to extend "Holy Touch" to the use of melee weapons, and in another step to ranged weapons. Or a reskinned version of toughness against supernaturals, representing how they hesitate to touch you. I think that would work way better.