Interior Bench III is built in the Church for 4 Wooden beam, 6 Iron Nails and 4 Fabric. +7 church quality. Unlocked by Church Illumination. Its construction site needs Building mastery 4: below that, hits do nothing.
It adds 7 to church quality. More elaborate sermons need a higher church quality. Each new best church quality counts towards the Sacred Interior inspiration. Church Illumination also unlocks Improve the Church III.