I kinda agree but i also disagree i didnt even thiught that wag begore readonb yoir comment I think when the author chose to portray the korean god(?) In a bad way is solely for the plot rather than presenting shamanism in bad and the fact ml is chirstan just comes in handy because it can be presented as a opposite opinion for the mc and i think taht gradually they would maybe just choose to be atheist maybe? Rather than chirstanity as the sole solution idk if you get what im saying

Idk if its just me, but this feels a little pro-christianity/christian-savior esque. From the beginning being a shaman has been portrayed as a negative aspect, with the MC's deity being a child grooming asshat willing to kill everyone around him in order to isolate him. The MC himself is living what most would consider a sinful life, conning people out of their money with fake charms and exorcisms, being obsessed with money and drinking in excess.
On the opposite side we have the heavily Christian ML, who is portrayed as the goodest (virgin) boy that's just really down on his luck. The MC keeps commenting on how pure and powerful his aura is because of how devout he is, to the point that it actually heals the MC's injuries and drives away ghosts (something the MC probably took years of training to be able to do, and ML just has to toss out a "BEGONE, DEMON!" paired with a handchop). He's even flat out told MC that he needs to convert.
Especially in these flashback chapters, it gives the vibe that the MC's deity and shamanism as a whole is dangerous and bad, and that Christianity is the love and light he's been missing from his life. It really feels like the story will end with the MC converting to Christianity and they combine their prayers into a Jesus Ray and blast the deity away team rocket style