All Truth is God's
Taking back what the unbeliever steals.
We may even take our apologetics one step further. We do not have to wait for anyone to object to our faith to engage in apologetics. When we understand what we do in apologetics, we will understand that we can engage the unbeliever at any time.
Indeed, we may press the gospel by actively opening the door for it by engaging the unbeliever and calling him to account for his worldview.
Think of it this way: The Bible says that â€œIn Christ are hidden all the treasures of wisdom and knowledge.â€ (Col. 2:3). In other words, our God is the author of all creation and the fountain of truth. Therefore it is legitimate to say that â€œAll truth is Godâ€™s truth.â€ More specifically, anyone who has truth, must take it from this God!
Since the unbeliever lives in this world he must hold to Godâ€™s truth to some degree in order to operate in this world. The unbeliever, then, is guilty of â€œstealingâ€ truth. He takes from the Christian worldview the truth that he has. Though he uses this truth, his worldview cannot account for that truth because it is not built on the revelation of God in Scripture.
So, wherever he makes use of truth, we may engage in presuppositional apologetics to expose how he does not have any grounds for making these claims to truth.
Hereâ€™s a concrete example: I was once talking with my neighbor about the girls my wife and I have adopted. As a man who travels to some rundown neighborhoods, he confessed to me that he is so glad that we have adopted and given these girls good homes. He went on and on about how â€œgoodâ€ it was.
We agree that adoption is good. That is to say, adoption has a moral dimension, and it is a â€œgoodâ€ and â€œdecentâ€ thing to give a child a good home. It is â€œnot goodâ€ to be in a broken home. Yet how can he, and unbeliever, account for these moral claims? Morality demands an absolute standard by which to judge good and evil. What standard does he have by which to measure â€œgoodnessâ€? We might ask him, â€œHow do you know that adoption is good?â€ His response would be something to the effect of â€œbecause I think it is.â€ We might then ask, â€œHow do you know you are right? What makes your personal inclination a valid measurement of what is good?â€
If he is honest (and it is likely that he wonâ€™t be), he will have to admit that his standard for judging morality is invalid. We could just as easily say, â€œAdoption is evilâ€ if it is up to our personal inclination. We know that adoption is good though. But why? It is because God has given us a standard for measuring what is good.
We have now just broken down my neighborâ€™s worldview, shown it to be absurd, and opened a door for the gospel. In just a matter of minutes we have shown him how his own worldview cannot account for morality (and is therefore absurd), and provided him a reason to acknowledge Christ as Lord.
All this is to say that it is only the Christian presuppositions that are able to give a coherent basis for reality, knowledge, and morality. Truth is Godâ€™s, and the unbeliever has no right to it apart from Christ.
Clarification: Do not misunderstand this: I am not saying that unbelievers do not have truth or morals. They most certainly do. It is part of the common grace that God grants them. All unbelievers have some degree of truth. What we want to do is show them that it is impossible to account for that truth in their system. In other words, we want them to confess the Source of that truth and acknowledge His standard for truth.
I once had a woman make this mistake. She said that we Christians donâ€™t think atheists have morals. I corrected her by saying that such wasnâ€™t true in the least. We do believe atheists have morals. However, we donâ€™t believe that they could account for those morals according to their system of unbelief.
The conversation involved discussion of her love to celebrate Christmas, despite her confessing being an atheist. I then explained that, if we are nothing more than cosmic dust (i.e. chance products of evolutionary change) it doesn't matter whether we eat the ham or the neighbor's child for Christmas dinner. If we are consistent atheists, one act is just as moral as the other.
How can I say this? It is because evolution does not give an absolute standard for morality. A child or a pig are essentially the same in that they are both chance products of evolution. No authoritative lawgiver has said that eating one or the other is wrong. Neither have they been endowed with any sort of dignity that would necessarily make such an act wrong.
The atheistic and evolutionary worldview, when critiqued by its own system, is not able to say that cannibalism is wrong. (If your lifeâ€™s maxim is â€œsurvival of the fittest, one might make the case that cannibalism ought be endorsed!â€)
To be sure, eating the neighbor kid should sound repulsive. It would be terrible if someone thought this was an okay thing to do. But how is it that this atheist could be repulsed by the thought of chewing on little Jenny from next door? It is because she steals from the Christian worldview. God has endowed man with a special dignity by creating man in His image. Cannibalism is forbidden (and reprehensible!) because it violates this basic glory given to man.
Again, all this is to say that all people have truth. Our question instead, revolves around how they account for that truth.
As Christians, it is our duty to "let God be true and every man a liar." So this tactic of vindicating God's truth is a wonderful means of accomplishing that very thing.