Some may wonder why seminaries teach church history classes. Is it really necessary for pastors to learn about key events and key persons from the past? I would argue that church history is not only necessary, it is essential. Church history helps familiarize pastors with major theological controversies of the past, which in turn helps prepare them for theological controversies today.
Most of the theological issues today have already been addressed and debated at some point in church history. As Solomon said, “What has been is what will be, and what has been done is what will be done, and there is nothing new under the sun. Is there a thing of which it is said, ‘See, this is new’? It has been already in the ages before us” (Ecclesiastes 1:9-10, ESV). Many “new” theological trends are simply old heresies warmed up. The following issues were addressed by the early church:
The Deity of Christ – In the 4th century, a man named Arius denied the full divinity of Jesus Christ. This teaching, which became known as Arianism, presented a major challenge to the early church and the biblical teaching concerning the person of Christ. In 325, the Council of Nicaea defended the deity of Christ and rejected the teachings of Arius.
The Depravity of Man – In the 4th and 5th century, a man named Pelagius basically denied the sinfulness of man. Pelagius argued that man was capable, if he so chose, of avoiding sin and choosing good. Augustine strongly challenged Pelagius’ views, and orthodoxy eventually won out. The early church recognized that Scripture teaches that man is not good; he is born with a sinful nature and is a child of wrath “by nature” (Ephesians 2:3, ESV).
The Trinity – Many people and groups have challenged the Trinity throughout church history. Sabellius, a teacher from the 3rd century, denied the Trinity and argued that God is one Person who manifests Himself in three “modes.” This view was at odds with the Apostles Creed, and the Council of Chalcedon rejected modalism and affirmed the Trinity.
What is interesting about the teachings listed above is that people still embrace them today. In the mid-20th century, the “modernists” or “liberals” denied the deity of Jesus Christ, and Jehovah’s Witnesses do not believe that Jesus was God. Some Christians today refuse to accept the biblical teaching that man is a sinner by nature and by choice. Certain groups (Oneness Penecostals and Jehovah’s Witnesses, for example) reject the Trinity. These heretical teachings, which the early church rejected, are alive and well today. Solomon was right. “There is nothing new under the sun.”
Studying church history will help pastors and Christians become familiar with the theological controversies, show them how the early church responded to these controversies, and help them defend orthodoxy and biblical truth. Far from being boring and unnecessary, church history helps pastors and Christians deal with false teaching by providing examples of how previous generations contended for the truth. If you are looking for a place to start, I would recommend Gregg Allison’s Historical Theology. It is part history, part theology, and it traces the historical development of all the key doctrines of Scripture.