Apologetics is the study of the defense of the Christian faith.
Many groups today claim to be apologists. They call themselves "cult watch" groups, and they have assigned themselves the task of defending the "historic Christian faith" from "cults" like the Mormons, the Jehovah's Witnesses, and the Way International.
Defending the faith is noble and commanded by Scripture …
One question, however, begs to be asked: what was the faith once for all delivered to the saints?
Unfortunately, most of those who claim to practice apologetics either don't know or don't care what it is.
I'll just be blunt with you. If you were part of a church that emphasized salvation by faith alone, a born again experience that is separate from baptism, and a baptism that is a symbolic public testimony, would you want to know that none of those doctrines are historic?
Most apologetics ("cult watch") groups are fundamentalist evangelicals. My experience with Christ—a very real and powerful experience—began in a fundamentalist evangelical church. Almost all fundamentalist evangelical churches teach salvation by faith alone, a born again experience that is separate from baptism, and a baptism that is a symbolic public testimony.
None of those doctrines, however, is historic.
Salvation by faith alone, as taught by apologetics groups like the Christian Research Institute, is not true. As taught by Paul in Rom. 3:28 and Eph. 2:8, it is true, because Paul taught in the same letters that works are required to go to heaven (Gal. 5:19-21; Eph. 5:5). (See my explanation of this.) Apologetics groups and many fundamentalist evangelicals do not believe that works are required to go to heaven. Thus, James specifically refutes those apologetics groups (Jam. 2:24).
There is some difficulty in proving from Scripture and history that the doctrine of sola fide as taught by cult watch groups is not historic, even though anyone familiar with the early church history can plainly see it's not historic.
Baptism, however, is so obvious that it's astonishing anyone can claim that symbolic baptism as a public testimony is historic.
There is not one Scripture suggesting baptism is symbolic, and almost every Scripture on baptism clearly states it is not just symbolic. The same is true of early church teaching on the subject. In fact, no one teaches a symbolic baptism or separates it from regeneration until at least the 17th century.
Baptism in water and the regeneration experience were clearly tied together in the eyes of all Christians until pietism took hold among the Lutherans. Before that, everyone believed that Jesus was talking about water baptism when he mentioned the new birth in John 3:3-5. Even Titus 3:5, which mentions "the washing of regeneration," was universally understood to refer to water baptism.
In Protestant churches it is common to appeal to the Scriptures apart from the historic witness of any church or any Christians as a source of authority. I do not want to argue that on this page.
On this page, I want to point out that apologetics groups claim to be teaching the historic Christian faith, not just what they believe the Scriptures to teach. They regularly refer to the great creeds and councils of Christianity as a standard of orthodoxy.
Those who are willing to be that confident (I hesitate to say arrogant, although I am certain that is how God sees it) of their Bible interpretation can take a stand against what the Christ's churches have historically believed. But you cannot set the historic Christian faith as a standard for Mormons, Jehovah's Witnesses, and other "cults," when you do not abide by it or believe it yourself!
The mid to late 2nd century Christian writers are known as the apologists. All of them appealed to the historic Christian faith.
The earlier apologists, such as Justin, didn't need to bother with researching the historic faith. For him and others of his age, just 50 years after the last apostle died, the historic Christian faith was still just what "we have been taught."
Later apologists, like Irenaeus and Tertullian, stated more precisely that they were leaning on a historic faith:
It is not that tradition has more authority or equal authority with Scripture. It is that tradition—if it can be shown to have come from the apostles and been handed down by the Church—judges interpretation of the Scriptures. This is proper apologetics …
Then, like now, heretics argued that it is the true church that corrupts the Scriptures and their interpretation, not themselves …
Proper apologetics, then, points to the historic Christian faith. What did the churches of the apostles believe?
That is not as easy to determine today as it was in Tertullian's day. Tertullian could go to a church formed by the apostles and ask what they had taught. He could compare it both with Scripture and the writings of those who had come before him, such as Clement, the Letter of Barnabas, and other writings.
Though it is more difficult today, it is not exceptionally difficult. We have those writings available ourselves. We have Tertullian's writings as well. Eusebius, in his Church History in A.D. 323, preserved many quotes from writings no longer available today.
Those writings are consistent, and they testify to one carefully defined and limited faith that is the faith for which Jude commanded us to earnestly contend.
Apologetics is still needed. There are modern heresies.
At what point have groups like the Jehovah's Witnesses and Mormons wandered from the faith? What about unusual groups that are not usually considered "cults," like the United Pentecostals or the Church of Christ, which divides from all other denominations?