It has been a long thinking theory of mine that it's really SON not sun. That it's actually the church guarding a portal or something.
1. Christian could turn into Christ son hence children of the sun.
2. Lot of holy artifacts out there but none are being used outside of the swords.
3. Hades has some there has to be more.
The first time I met that sun/son pun I think was a ST:TOS episode.
And sometimes I see people go "Christ..." plus "...tian" is kinda "...son" so we'll go with that.
I don't think it's so -- not in the Dresdenverse -- because we have both in-world/canonical and meta/WoJ confirmation that Uriel is "erase an entire solar-system with a thought" level of powerful. Also, I'm pretty sure Mab or Lea have used "the White God" or similar, with no hints of "sun" iconography.
OTOH, we've seen that one of the most pervasive and potent magical forces -- hitting the whole world, every day -- is the
sunrise; and the sun has special potency against Rampires, Blampires, and various spirits; and remember when Harry tried to use "Uri" as a nickname for Uriel? Harry had to come up with another name:
Mr. Sunshine, and there's more than one syncretic tradition in the 0CE-300CE era that conflates Christ with Apollo (he of the sun-chariot). So some sort of sun / Christian linkage seems possible.