There are two fundamental points at which Rome deviates concerning the Bible on the Bible’s view of itself:
First, Rome denies that the Bible is a self-interpreting revelation. The Bible declares itself to be self-explanatory. This is called the doctrine of the perspicuity of the Scriptures (the see-through-ableness of the Scripture). It may be understood in its own light. What is obscure in one passage will be clearer in another. What is incomplete here is completed there. What is a figure in one place is a commentary in another.
Rome has substituted for the doctrine of the perspicuity of the Scriptures the doctrine of the audacity of the Church. The Bible says that those who run may read; Rome says that those who run to her may read. The Bible says of the Bereans who searched the Scriptures that they were noble; Rome says of the Reformers who searched the Scriptures that they were heretics. The Scriptures say, “Study to show thyself approved unto God, a workman that needeth not to be ashamed, rightly dividing the word of truth,” 2 Timothy 2:15. Rome says, “Study to show thyself a slave obediently accepting the word of Rome.”
“But,” the Roman Catholic church maintains, “the Word of God needs an interpreter.”
“If so,” replies the Protestant church, “the word of the pope also requires an interpreter.” If the Bible must be interpreted by the Church in order to render its meaning certain, then the interpretation of the Church will have to be interpreted by another authority to make its meaning certain, and then there will need to be an interpreter of the interpreter, and so on ad infinitum.
Now if the Romanist replies, “Where there are divergent views on the Bible teaching there must be some authoritative decision,” we will agree. Nor do we only agree. Our various Protestant church courts actually provide authoritative interpretations on most points when such decisions are necessary. But there is a difference between authoritative and infallible decisions. Compare, for example, the necessity for an authoritative interpretation of the Constitution. A Supreme Court performs that task. Yet what American believes the Supreme Court is infallible? Still, its decisions prevail as a matter of necessity. On occasions the Court may be “stacked” and its interpretations biased. In the long run, however, the people of this land believe an authoritative interpreter necessary, but never do they regard it as infallible. The Constitution remains the law of the land, not the Supreme Court. Likewise, the Bible remains the law of the Christian, not the Church.
The Roman Catholic church proclaims itself to be “the pillar and ground of the truth,” since 1 Timothy 3:15 says that the church is the pillar and ground of the truth. But that verse does not say that the Roman Catholic church is the pillar and ground of the truth; in fact, the Roman Catholic church did not even exist when this verse was penned. Additionally, where did the Church get the idea that it is the pillar and ground of the truth? From the Bible! It is the Bible which is the basis of the church’s authority, not the church which is the basis for the Bible’s authority. The Bible is the pillar on which the church rests; the church is not the pillar on which the Bible rests. Incidentally, the expression that the church is the pillar and ground of the truth does not point to a pillar on which truth rests, but to a pillar on which truth was posted for public announcement in antiquity. In other words, it refers to the church as witness to the truth and not the basis of it.
The Protestant church has provided for authority so that decisions can be rendered when necessary, but has avoided the error of investing this authority with infallibility. The Protestant church, not being infallible, can err, has erred, will err. There is one error, however, which it has not made and that is the greatest of them all—the error of thinking it cannot err.
Having considered Rome’s first great denial, namely, that the Scripture is self-interpreting, we will consider her second great denial: that the Scripture is a complete revelation.
“Wherein is the Scripture incomplete?” we ask. No infallible answer has been given to that question, but there are a dozen or more doctrines which the majority of Roman theologians agree are only imperfectly revealed in the Bible, or merely implied, or entirely omitted.
Let us examine one of each of these classes. The Trinity, for example, Rome regards as imperfectly revealed in the Scripture. What, then, has the Church added? That God is one as to substance and three as to person. We agree. But still our philosophical interpretation of the simple Bible teaching may turn out to be quite wrong. And besides, the important thing is that God is one God and yet three persons, not how He thus exists. Yes, something new has been added (that the substance and personality of God are distinguishable) but it may be wrong. Furthermore, the explanation is not necessary to a knowledge of the Trinity. And finally, what is necessary and certain is already contained in the Bible.
Note as an example of the second group, doctrines merely implied, infant baptism. Church practice sanctions this rite. Well and good. But how did the Church come to sanction it? Undoubtedly because the Church believed that infant baptism was clearly implied in the Scripture! So the very Church tradition that is supposed to add force to the Bible rests on the Bible and has no more validity than the biblical implication.
Note finally as an example of the third class, doctrines entirely omitted in the Bible, purgatory. Here Rome is creating her doctrine out of whole cloth. Purgatory is not only omitted by the Bible, it is utterly precluded by the constant biblical teaching of two and only two possible destinies which face every man.
In order to harmonize such doctrines as purgatory, the immaculate conception of Mary, the infallibility of the pope’s official declarations, etc., Rome is obliged to wrest the Scriptures. She is no more able to serve the two masters, tradition and the Scriptures, than were the Pharisees. She has had to cleave to one and abhor the other. Unfortunately, it has been the word of man rather than the Word of God which has been the preferred master.
This reminds me of the art collector who had a painting of the Leaning Tower of Pisa in his office. Each morning when he came in he would notice that the painting was hanging askew. Finally, his bewilderment drove him to ask the maid if she knew how it happened that every morning the painting was askew. She had a ready explanation: “I have to fix it that way in order to make the tower hang straight.” Rome, likewise, is obliged to wrest the Scriptures in order to allow her tradition to hang straight.
Excerpted from Primitive Theology by John H. Gerstner.
Note: This primer is intended to give an overview of the significant theological differences between historic Protestantism and historic Roman Catholicism. In a primer of this size, it is not possible to give a thorough examination of a theology that has been controverted for centuries. For a fuller treatment of the main difference between Catholicism and Protestantism—justification by faith alone—see Justification by Faith Alone or, for Dr. Sproul's response to "Evangelicals and Catholics Together," see Getting the Gospel Right: The Tie That Binds Evangelicals Together.