We’re not so easy to find, being up in the hills on the Sourland Mountain, so here are some hints and pointers.  The address is:

Mt. Zion United Methodist Church
478 Long Hill Road
Hillsborough, NJ  08844

The church is on Long Hill Road, between Montgomery Road and Spring Hill Road.  If you come up Hollow Road from CR 518, turn left onto Long Hill Road, and the church will be 1/4 mile on your right.  Note that just after the church, the road changes its name from Long Hill Road to Zion-Wertsville Road, which can be very confusing to you and your GPS.  For the technical, the coordinates of the church are:  40.437568, -74.743448

Link to Google Street View:  Google Maps