Not a manwha but Sasaki to miyano fits the bill
Lowkey far from home would be a good fit since it deals with literally both.
https://www.mangago.me/read-manga/haruka_tooki_ie/
If they are ready to cry and bawl there eyes out. Then follow it up with Twilight out of focus. They are gonna be HOOKED
*far away home
I'd focus on sharing mostly shonen ai stories, since he's religious and just got his awakening he might not feel that comfortable seeing to men going at it. Here are some recs that are interesting and have little to no sex scenes.
https://www.mangago.me/read-manga/there_s_something_wrong_with_my_popularity/
https://www.mangago.me/read-manga/the_polaris/
https://www.mangago.me/read-manga/to_be_or_not_to_be/
https://www.mangago.me/read-manga/i_became_the_lousy_side_top_official/
https://www.mangago.me/read-manga/10_years_where_i_loved_you_the_most/
https://www.mangago.me/read-manga/indulged_in_your_light/
(I'd use this one if he's ready) https://www.mangago.me/read-manga/semantic_error/
A home far away is the best for her.
Reunion
Touch within the abyss
These are bestest for her.
Definitely 19 days
Merry Marbling
Sasaki to Miyano
So the way I recommend introducing these by asking him to read these like he's just reading another shoujo or romance manga. These are just romance mangas, don't start reading it knowing that they are two men falling in love and instead see it as two regular people who fell for each other just as naturally as a man and a woman would.
also important note: in this site the one tagged as yaoi has light to full smut. the ones tagged as shounen ai has absolutely no smut.
- made me cry but in like a really good way
https://www.mangago.me/read-manga/life_senjou_no_bokura/
- drop dead gorgeous masterpiece (light smut near end)
https://www.mangago.me/read-manga/kimi_no_yoru_ni_fureru/
- classic story with realistic conflict. really drives the point that gay people didn't chose to be gay, love just appears like that for them
https://www.mangago.me/recommend-manga/see_you_later_mermaid/
- short and old but it gives an outsiders perspective on a gay couple and very realistic
https://www.mangago.me/read-manga/ani_no_hanashi/
- semi fantasy (it's tagged as yaoi but it has 2 scenes of light smut with one extra chapter that's a more heavier smut)
https://www.mangago.me/read-manga/barefoot_angel/
- this one is full-on fantasy but very very beautiful (light skippable smut)
https://www.mangago.me/read-manga/yoake_no_uta/
- two boys who hilariously accidentally fell in love with each other (this one's long)
https://www.mangago.me/read-manga/faded_first_love/
- a meet-cute casual love story
https://www.mangago.me/read-manga/tonari_no_metaller_san/
- edgier humour, comedy with it's serious bits (one scene with implied smut)
https://www.mangago.me/read-manga/daraku_kazoku_ron/
- a casual love story that rougher around the edges but it's very well thought up while still being light hearted
https://www.mangago.me/recommend-manga/the_eve_festival/
- love between older gay men. very realistic in its frustrations but very very cute overall (light skippable smut)
https://www.mangago.me/read-manga/lovers_on_the_last_train/
If he gets tired of reading I recommend making him watch these two movies: Dokyuusei and Umibe no Étranger. I tried really hard to make this list with as much consideration as I could. Remember, if he's still learning about all this and doesn't understand or like a few things please be patient and try to educate him as best as you can. Thank you for opening him to LGBT mangas.
I got a friend who's religious asf and got his own awakening, told me that he's curious and would like to try reading em. Any genre is fine, not too problematic or too angsty hopefully. No smut preferably as well, but light ones is oksie. BLs manwhas that would make you realize "holy shit being gay is good and fine and it's totally not a sin bcs love dgaf abt gender"