Does a neutral wire need to be run from a switch to the light?
A church is a commercial facility so use caution on advice received on this site most are not familiar with the unique requirements to commercial construction. Could you provide a photo of the wires entering the box?
Also how many lights and the type?
there may be a contactor controlling multiple runs I use 3 phase contactors to control 3ea 20 amp strings on 120/240v services.
there are timers that need no neutral check out an intermatic STO1 they run in the mid 30$ range and the timer is battery powered so no neutral is needed and power bumps don’t affect it. The battery last about 2 years.
The nice thing about this timer is it is astrometric or you can turn on a feature to turn on at sunset and off at sun rise it updates itself based on your location. I use them at my plant to turn the yard lights on at 3am then off at sunset, on again at sun set then off at 1030 pm or the time they shut down for that day then they don’t turn on for a day that we never work would be great for a church where scheduled services and weekly Bible studies or choir practices. If you need it on when it’s not programmed tap it and it will stay on until tapped again or the next scheduled off time. I drive small (15 &amp; 20 amp circuits) with this timer and if the loads are larger drive contactors (power relays).
Depending on the area and construction type you may have conduit that’s why I asked for a photo and a neutral could be pulled in conduit in commercial facilities. buildings with occupancy requirements are normally wired with conduit.