I've been playing Deify (Deify: A mythical solo role-playing game) and i realised it's kind of perfect if you want to play a cleric or holy Paladin in another game like DnD, cause you can make a custom deity and religion.
You can make practices, figure out what your character could consider sacred, and what epithets your deity could go by.
That way you could use custom prayers and practices to roleplay your character.
I think it would be kind of incredible to make a cleric based on a Deify game, you would have so much personalised reference material to make a really in depth character and roleplay really well.