So i play Deltarune and Undertale and i have a problem

Kris and frisk and chara are nonbinary but i don't know and don't understand what that means or even know how to use they and them for one person it just doesn't make sense to me it's not in my linguistics

and i just can't comprehend it frisk and kris look like boys and chara looks like a girl and i just call kris he and frisk he and chara she

cause it makes sense to me cause of what the bible says about gender and stuff

but when i say this in the deltarune/undertale community i get hate i don't mean any harm i just don't know what i'm supposed to do PLEASE HELP!?