There are several fee-based garages nearby. Some that we recommend (all in the 19103 zip code) are:
Parkway Corporation Parking Lots and Garages
2401 Walnut Street (enter at 24th and Sansom Streets)
210 South Walnut Street (also enter at 1906 Walnut Street)
The Rittenhouse Garage, 214 South 20th Street
1847 Walnut Street (also enter at 1815 Sansom Street)
Park America Garages
2027 Sansom Street
Penn-Warwick Garage at the Radisson, 220 South 17th Street
23rd and Ludlow Street
2102 Sansom Street
2107 Sansom Street
The Philadelphia Parking Authority offers a parking app called Park Me, which you can find here, to help find a parking space within one of these lots.
Free or metered on-street parking in the vicinity is very limited and requires relocating the vehicle throughout the day.
Several local bus routes provide service near the church. SEPTA Regional Rail lines can be accessed at either 30th Street Station or Suburban Station. The Trinity Center for Urban Life Web site provides excellent information about public transportation and parking as well.