Please recommend me a novel where the MC is pretty much viewed as a saint in a good way. A protagonist that would wish best for everybody. A naive-like sense of optimism and goodwill, but has the backbone and ability to back those ideals up. I don't want his kindness to be a false front, I want him to legitimately sincere and honest to himself and other people. A good example would be Saihate No Paladin
Would manga be OK? Cuz I'm just dying to recommend a particular manga here. It's Machida-kun no Sekai.
https://www.novelupdates.com/series/the-famous-millionaire/ https://www.novelupdates.com/series/legend-of-legends/
Tale of a lax demon she is a saint (though she's a demon) she loves humans (cause their souls are delicious) she is very easy going (lax) her kindness is genuine (letting souls mature makes them more delicious) she is sincere with her own desires the only thing that might not fit your requirements might be the fact that the mc is female...
Cultivation Chat Group... Besides the evil people most people think of him as the nice guy rather than a saint
Doomsday Wonderland. The MC has a hero complex that even she herself is aware of. It's a female protagonist tho