Not all apologists will answer the question of whether or not it's possible to arrive at a place of rational certainty regarding the Christian faith identically. Popular Campus Crusade speaker Josh McDowell addresses the issue this way:
Many times during conversations relating to truth, particularly religious truth, someone asks the question, 'Can you prove Christianity to be true?' Most often, however, the question is phrased, "Can you say 100% for certain that Christianity is true?" The answer to the first question is, "Yes, Christianity can be proven to be true." This of course does not mean that everyone will accept the evidence, however good it is. But the answer to the second question is, "No, not 100% for certain."... Everybody makes the decisions of life based on probability, not certainty. Decisions are based on a combination of faith related to fact. For example, a person about to cross a road stands on one side, looks both directions (hopefully he does!), collecting the evidence necessary to determine the probability of making the journey across in safety...To those outside the Christian faith, Christianity can be shown to rest on strong evidence and have a high degree of probability for its truth claims.1
McDowell does say that after "a person becomes a Christian, the 'assurance' or 'certainty' becomes a reality. Christianity from a 'morally certain' standpoint becomes as undeniable as one's own existence."2 So in McDowell's view there appears to be a moral certainty that may be achieved by a believer even if there isn't a 100% rational certainty. Whether or not such a distinction can be made is not the subject of this essay. It is enough to understand that McDowell regards "rational certainty" as less than absolute.
Christian author Lee Strobel echoes this same view when speaking about the proof of Christianity. He writes, "Ultimately its the responsibility of jurors to reach a verdict. That doesn't mean they have one-hundred percent-certainty, because we can't have absolute proof about anything in life. In a trial, jurors are asked to weigh the evidence and come to the best possible conclusion."3
The above responses would no doubt match those of a great many Christian believers. The question before us is whether or not this notion is justified by what the Bible itself says about the knowledge of God. In Romans 1:18-20 the Apostle Paul wrote:
The wrath of God is being revealed from heaven against all the godlessness and wickedness of men who suppress the truth by their wickedness, since what may be known about God is plain to them, because God has made it plain to them. For since the creation of the world God's invisible qualities — his eternal power and divine nature — have been clearly seen, being understood from what has been made, so that men are without excuse.
Paul says the knowledge of God is plainly revealed to all men. Both Psalms14:1 and 53:1 say that "The fool says in his heart, 'There is no God.'" Apparently, true knowledge of God among men is so obvious that only the foolish try to pretend otherwise. The Apostle John wrote that Christ is the true light that gives light to every man that comes into the world (John 1:9). In Lystra Paul preached, "Yet he has not left himself without testimony: He has shown kindness by giving you rain from heaven and crops in their seasons; he provides you with plenty of food and fills your hearts with joy" (Acts 14:17).
God's revelation of Himself to man is so inescapable that man's rejection of the one true God is inexcusable. "If I ascend up into heaven, thou art there: if I make my bed in hell, behold, thou art there" (Psalm 139:8). This kind of knowledge of God is not saving knowledge to be sure, but knowledge that establishes men's guilt before God.
The reason many Christian apologists say that the question of certainty about our Christian faith is less than complete is because their acknowledged starting point for answering these questions is human reason. While the mind of man may seem to be the natural logical starting point for most people to begin answering rational questions an honest inquirer would have to admit that the notion of using human reason as an ultimate authority, rather than as a tool, has a built in problem. Francis Schaeffer summarized this problem by pointing out that it is generally assumed that "man, beginning totally independently and autonomously, can build a bridge towards ultimate truth — as if attempting to build a cantilever bridge out from himself across an infinite gorge. This is not possible, because man is finite and, as such, he has nothing toward which he can point with certainty. He has no way, beginning from himself, to set up sufficient universals."4
Human reason resides within finite creatures and therefore should never be regarded as either self-sufficient or the ultimate authority for anyone. There is an inherent lack of certainty within finite human reason that will always prevent the one who begins with it and ends with it as their supreme authority from ever being able to say that they have "arrived" at the point of rational certainty in their beliefs. So then where else must we begin our thinking process? To answer this one must first ask, "What is it that supports human reason?" In other words, what is the metaphysical foundation or precondition for man's reasoning?
The scripture records that God created man in His image. God communicated some of his attributes to man, albeit on a finite scale. As part of the communicable attributes God imparted to man's nature is what we call "mind." Man has the finite capability to think and reason logically along the same lines as his Creator. Therefore, when men think true thoughts, they are in essence thinking God's thoughts after Him, although on a creaturely scale. Thus, all true knowledge has its roots in the God who provides the metaphysical foundation for it. "The fear of the Lord is the beginning of knowledge, but fools despise wisdom and discipline (Prov. 1:7). In Christ are "hidden all the treasures of wisdom and knowledge" (Col. 2:3). Jesus Christ is "the way and the truth and the life…" (John 14:6).
Reformed Christian apologist Cornelius Van Til, like John Calvin and other theologians before him took into account the scripture's teaching that human reason does not stand on its own. He saw in the scriptures that every man's metaphysical dependence upon God in the area of knowledge was total and that the creation established by God, which is revealed in part within the scriptures, provides the only possible basis for man's reason. This means that all men, including unregenerate men, cannot reason at all apart from the truths contained within the Bible. Even though they will deny it, unbelievers are forced to operate upon biblical truth in their everyday existence because biblical truth alone can account for man's ability to think and reason. Van Til pointed out that the very fact man is a self-conscious creature necessarily presupposes the metaphysical realities revealed in the Bible.
In short, the Bible itself provides the only possible metaphysical basis for enabling all men, Christian believers and non-Christians alike, to reason in the first place. Now, if the Bible alone can account for the existence and ongoing use of what men call "reason," then 100% certainty about Christianity is possible. In Van Til's view, the very truths taught in the scriptures that the unregenerate thinker seeks to rationally reject are the very truths that can alone account for the human reason being exercised by the non-Christian. This is exactly the kind of inescapable knowledge of God the scriptures teach all men possess.
Since human beings are a part of God's creation Van Til observed that their "own constitution so clearly evinces the facts of God's creation of them and control over them that there is no man who can possibly escape observing it. If he is self-conscious at all he is also God-conscious."5 Van Til also concurred with Calvin that "as created in God's image every man, of necessity, has a knowledge of God. This 'innate knowledge' is correlative to God's revelation in man's environment. And try as he may the sinner cannot efface this knowledge. He can only seek to suppress it."6 Van Til attempted to demonstrate in his apologetic that the "The finite human consciousness is itself revelational of God."7
This is why Van Til's presuppositional apologetic is to be distinguished from other apologetical methods. By relying upon the truth contained within the scriptures — that it is impossible for man to know any aspect of reality apart from the God of the Bible — Van Til answered the question about being 100% certain of the truth of Christianity differently than most contemporary apologists. His apologetic is revolutionary because it unapologetically begins with the sure foundation of truth that only God Himself could supply in His own written Word.
1. Josh McDowell and Don Stewart, Answers To Tough Questions (San Bernardino, CA: Here's Life Publishers, 1990), pp. 145-146.
2. Ibid., p. 146.
3. Lee Strobel, The Case For Christ (Grand Rapids, MI: Zondervan Publishing House, 1998), p. 15.
4. Francis A. Schaeffer, Trilogy (Westchester, Illinois: Crossway Books, 1990), p. 266.
5. Cornelius Van Til quoted in Greg L. Bahnsen, Van Til's Apologetic: Readings & Analysis (Phillipsburg, NJ: P&R Publishing, 1998), p191.
7. Ibid., p. 221.