The church was probably the second most important social institution in developing a system of values and a "style of life" in the Fair Play territory. Here again, the Scotch-Irish with their Presbyterianism provided the most significant influence, and ultimately the first regular church—although Methodists, such as Colbert, found little to favor in Calvinism. Almost without exception, the wills probated in the courts of Northumberland and Lycoming counties between 1772 and 1830 asked for burial "in a decent and Christian like manner," and committed the departed soul to "the Creator." A Christian life and a Christian burial were valued in this frontier society.

Due to the absence of regular churches, religious instruction was primarily carried on by mothers "abel to instruct," as Mrs. Hamilton put it.[31] Prayer, the reading of the Bible, and a rudimentary catechism were all a part of this home worship, conducted by one or both parents. Baptism and other sacraments of the church were provided by itinerant pastors who made their "rounds" through the valley. Presbyterians and, later, Methodists developed the practice of gathering together in their cabins in "praying societies."[32] Originally consisting of neighbor groups, these societies, in time, took in areas consisting of several miles.[33]

Itinerant pastors began to include the Fair Play territory in their travels in the decade of the 1770's. Philip Vickers Fithian learned from his host, Squire Fleming, that he was the first "orderly" preacher in the area.[34] Fithian's visit came about after he obtained an honorable dismissal from the first Philadelphia Presbytery—as no vacancies existed—in order to preach outside its bounds.[35] Although in the territory for only one week in the summer of 1775, Fithian's account of his Sunday sermon on the banks of the Susquehanna clearly describes the nature of wilderness preaching:

At eleven I began Service. We crossed over to the Indian Land, & held Worship on the Bank of the River, opposite to the Great Island, about a Mile & a half below 'Squire Fleming's. There were present about an Hundred & forty; I stood at the Root of a great Tree, & the People sitting in the Bushes, & green Grass round me.

They gave great Attention. I had the Eyes of all upon me. I spoke with some Force, & pretty loud. I recommended to them earnestly the religious Observation of God's Sabbaths, in this remote Place, where they seldom have the Gospel preached—that they should attend with Carefulness & Reverence upon it when it is among them—And that they ought to strive to have it established here.[36]

Fithian's recommendation was not carried out until 1792, when the Pine Creek Church was organized under the historic "independence" elm with Robert Love and a Mr. Culbertson as the first elders.[37] This church, along with the Lycoming Church, which was formed in the eastern part of the former Fair Play territory in October of that same year, was served by the Reverend Isaac Grier, who was called to serve Lycoming Creek, Pine Creek, and the Great Island, and ordained and installed by the Carlisle Presbytery, April 9, 1794.[38] He thus became the first regularly installed pastor in what had been the Fair Play territory.

It was not until 1811 that the Presbyterian General Assembly organized the Northumberland Presbytery, which serves West Branch Valley Presbyterians to this day. In the days of the Fair Play system the area was assigned to Donegal Presbytery, although in 1786 the Carlisle Presbytery was formed out of the western part of Donegal.[39]

Missionary efforts of Presbyterians in the Fair Play territory go all the way back to September of 1746, when the Reverend David Brainerd preached to the Indians of the Great Island.[40] But from that time until the opening of the West Branch Valley to settlement, following the first treaty at Fort Stanwix, nothing concerning the area appears on presbytery records. However, after the treaty one Presbyterian minister, the Reverend Francis Alison, pastor of the First Presbyterian Church of Philadelphia and vice-provost of the College of Philadelphia, applied for land above the mouth of Bald Eagle Creek and was granted some 1,500 acres.[41] Alison never came into the region and, in fact, sold his entire purchase to John Fleming in 1773.[42]

Although Fithian was the first "orderly" preacher assigned to the West Branch, the Donegal Presbytery had received an application from "setlers upon the W. Branch of Susquehannah" for ministerial supplies (pastors) in the middle of April, 1772.[43] Apparently these supplies never reached north of present-day Lewisburg.