Churches are buildings used by Scholars to hire preachers and give sermons. It can be used to produce a variety of goods including host, holy water, parchment, poems, and thesis papers. It can be upgraded into a Dome, and eventually into a Cathedral.
Domes or Cathedrals with the reliquary upgrade make it possible for a Scholar and his preachers to gain believers, converting their townspeople to their faith.
Cathedrals with the votive image upgrade make it possible for a Scholar and his preachers to pray for God's protection, making buildings immune to sabotage for 24 hours.