I'm not very happy with this piece. I'm struggling to get out of an art block right now :U
You can look at this piece one of two ways:
A. They're two homosexual priests struggling with their love versus a religion that condemns it.
B. Canon SebastianxAdult!Ciel come before God to plead mercy on their love, permission for a demon to have a single thing that makes him happy.
As such, Sebastian also has to kinda repent for his sins. As you can see, even entering a church causes pain for Sebastian.
and you all know i love my repentant Seb, even if I don't care for the religion itself. c: