The jumpscares in the opening scene of sinners are placed so well and are so thought out i love it
The cuts to Remmick happen when Jedidiah (the priest and Sammie's dad) reaches out in similar ways as he did. The jumpscares act as both foreshadowing of what is to come and they show the similarity between Remmick and Jedidiah.
The characters mirror each other because they both present themselves as saviors to Sammie. Because they are both false saviors. They are two sides of the same coin. They both want to lay claim over Sammie's music, his soul. Jedidiah might say he wants Sammie to put the guitar down, but the movie (and the soundtrack song this little light of mine) shows he has no actual problem with the music so long as it is used in favour of his God and christianity.
They both want for Sammie's music to not be his own anymore.
Remmick wants it for himself
Jedidiah wants it for God (and arguable also himself)