Mark Craddock (of the incredibly useful Crossplanes blog) was kind enough to provide me some of his 5th edition resources on DMsguild.com, and I've had some opportunities to try them out. Given that it can be hard to sort out all the content on DMsguild, it seems like a good idea going forward to talk about the useful stuff you can find out there.....and Mark has got some very useful stuff indeed, especially if you are a player.
First up are two tomes: Deities & Domains and it's sequel, Deities & Domains 2, which are two Forgotten Realms-focused adaptations of the classic priests of specific deities from AD&D 2nd Edition. Each book uses the feat system to create a way to add the flavor of a priest dedicated to a specific deity; this is slightly different in approach from, say, adapting a new domain to the cleric class, and it lets the cleric use the first feat slot he or she gains to add specific deity-themed abilities and flavor to the clerical style.
Book one is 24 pages long and includes 39 divine feats, which cover most of the Faerunian deities I am familiar with in my (admittedly limited) knowledge of the Forgotten Realms. Book 2 is only 10 pages and adds 11 more feats of some more obscure deities. Both books address a bit as to what happens if you fall out of favor with your chosen deity.
The upside of these tomes is they give you everything you need to quickly integrate Faerunian deities in to your game. In reading though the tome I did not find any feat that seemed out of balance compared to the standard practice of 5th edition feat design, which was good....and I think I could use these for my homebrew games with suitable reskinning (a release which provides generic non-setting-specific feats of such a nature sure would be cool though, hint hint!)
The downside of these two tomes is that they do require the use of a feat slot, which is both mighty and precious in 5th edition; it removes direct "flavor" as part of the process of the cleric class itself. However, this keeps everything mechanically balanced, which can be a big plus to some.
If you'd like a resource to go with older FR 2nd edition AD&D books, or you are just craving more FR content beyond the Sword Coast Adventurer's Guide (which so far as I recall does little to suggest how to integrate specific deity worship with the cleric class) then I think you'll find these very useful. You may also find them very useful to reskin for your own home campaigns, too.