Thorn City had a total of eight churches of the Holy Spirits Church. This was the same configuration as most large cities. Every parish of the Eight Holy Spirits had one.
The Holy Spirits Church wasn't just a place that was in charge of satisfying the people's faith needs. A considerable portion of the municipal functions was handled by the different churches of the Church.
For example, the Funeral Church of the Seventh Holy Spirit, the Dead, was in charge of the requiem, cremation, sacrifice, and related work for the dead. As for where ghosts usually appeared or where an undead suddenly appeared in an ancient grave in the nearby countryside, it was usually handled by the Funeral Church's Requiem Soul Masters. Of course, they would also collect the corresponding fees.