First Presbyterian Church was formed in 1869 by the Northumberland Presbytery and is the oldest church in Montgomery. On land given by the Barber and Henderson families, a cornerstone was laid in 1872 and the building was completed in 1875, when the first church service was held with Reverend Alvin Cutler Campbell leading worship. In 1931, First Presbyterian Church merged with the Grace German Reformed congregation to form Grace Presbyterian Church. The original building lacked a center aisle and had colonial style box pews and coal oil lamps lowered from the ceiling; electricity was added in 1902, central heating in 1903, a manse was built on the adjoining lot in 1906 and later demolished in 2008, and a basement was dug in 1914. In 1931, memorial windows and altar furnishings were among new items dedicated. The stained-glass windows were made by the Haskins Studio using imported cathedral glass with light tints, giving the effect of antique windows. The "Rock of Ages" mural was painted on the chancel wall in 1946 by Heilhecker Sign Studio of Williamsport and was reproduced in 2022 by a local artist. The church has long been a focal point for community gathering, including a memorial service for President Grant sponsored by the local G.A.R. post, a Memorial Day service after World War II honoring the Decker boys who were killed in action, and use of the basement as a canteen for teens and for Scout groups. In 1877, one of the railroads gave the church a bell inscribed "Vanduzen and Tift Cincinnati Buckeye Bell Foundry." The bell was rung to mark significant national events, including the 1901 deaths of President William McKinley and Queen Victoria, the end of World War II in 1945, and at noon in 1981 for the freeing of the hostages taken at the American Embassy in Iran. The most recent renovation was completed in 2022, when a new blue tin roof was installed and the interior walls and ceiling were repaired and painted, and the church continues to have a vital ministry in the community.