聖キリアン
Mars has several Christian denominations located within and just outside the community. One of the largest churches was Saint Kilian Parish. Founded in 1917, the parish was originally located in downtown Mars, but by the early 2000s (decade), membership had swelled so much that a new facility was constructed just outside the neighboring Seven Fields borough along PA 228 in 2008. There is also a large presence of Presbyterians in the borough. The Mars United Presbyterian was founded in 1969 with the merging of two older churches, one under the United Presbyterian Church of North America, the other under the Presbyterian Church (U.S.A.). There is also a Lutheran and Methodist church located within the borough. The Woodland Valley Church is one of the newer churches in Mars, and is one of several contemporary churches that have recently started in the Mars/Cranberry area. Others include the Mars Alliance Church, and the Discovery Christian Church which will be built along PA 228 across from the former. The Serbian Orthodox Eparchy of Eastern America previously had its headquarters in Adams Township, near Mars.