Coopersburg, located along the south branch of Saucon Creek, was one of the first villages to be settled in the Lehigh Valley. It soon became a center of cooperation among Mennonites, Moravians, Lutheran and Reformed traditions for worship. Coopersburg is surrounded by low lying hills to the west, south and east. Both valley and hills were covered with fertile limestone soil which attracted settlers as early as 1730. The people of Coopersburg worshiped at St. Paul's Blue Church, the Saucon Mennonite church and at three churches located outside of Coopersburg.

Although there is historical evidence indicating that Lutheran Christians had moved into the Saucon Valley and began worship together as early as 1732, the first recorded meeting of the Blue Church congregation occurred in 1739. Originally known simply as the "Saucon Church" (referring to the nearby Saucon Creek), the congregation was comprised of farmers and tradespeople who moved into the area recently traversed by Native Americans.

The congregation took possession of and began occupying its present site in the early 1740's. The first building was a simple stone and wood structure not far from the present building. The location along a water source (several springs are on the church property) was a major factor in building on the site. The first parishioners were often poor and were served by itinerant clergy and lay leaders with an inclination to preach. The first regular Lutheran pastor was Henry Melchior Muhlenberg, who arrived in 1745 and helped organize and solidify the congregation in the Lutheran fold. Subsequently, the Saucon Church sent representatives to the first meeting of the Ministerium of Pennsylvania, held in Germantown (now part of Philadelphia) in 1748. Blue Church is one of 8 congregations still in existence from the 10 original congregations that chartered the Ministerium.

A second building, a wooden clapboard structure, was erected in the 1750's and stood until the present stone structure was built in 1833. The first cemetery was opened in 1750 and serves as the burial ground for American military veterans of all but the most recent wars.

The name of the congregation was officially changed to St. Paul's Lutheran Church when the current building was dedicated in 1833. For many years the stone structure was covered with stucco, which was eventually painted blue, leading to the label "Blue Church."