Philip Schaff (January 1, 1819 – October 20, 1893) was a Swiss-born, German-educated Protestant theologian and ecclesiastical historian, who spent most of his adult life living and teaching in the United States.

Renwick suggests a fourfold division of church history into missionary activity, church organization, doctrine and "the effect on human life". Church history is often, but not always, studied from a Christian perspective.

A generation has grown up unaware of the basic truths of the Christian faith taught in the Scriptures and expressed in the creeds of the historic evangelical churches." Its first editor was Carl F. H. Henry.

After the event of Pentecost, during which the descent of the Holy Spirit had occurred, and many among the audience of the Apostle Peter converted to Christianity, the faith in Christ was consolidated and the newly catechized together with the Apostles formed the First Church of Jerusalem.