The worship of Mystra, the goddess of magic and arcane mysteries, was widespread in The Sword Coast. The Dragon Friends have encountered two temples of Mystra in their travels: in Daggerford and in Waterdeep.
More info on Mystra can be found at the Forgotten Realms Wiki.
The Temple of Mystra in Daggerford was run by Mistress Lorna and housed numerous acolytes many of whom (including Freezo) were orphans or foundlings left in their care. The Temple also opened its doors to holy travelers and paladins such as Kithercy Gellantara.
Acolytes of the temple took vows of poverty, living in small rooms on a simple diet of quinoa mush.
As above, but supplementing temple income through the sale of sunglasses.
Freezo spent much of the Dragon Friends' Waterdeep adventures apart from the group, spending his time alone in the Temple. The Waterdeep temple also provided healing services for Janos Meer in the aftermath of The Shipyard Betrayal.