The prospect of commending the Christian faith is sometimes daunting for seasoned saints and new converts alike. Often what makes believers so nervous is their perceived lack of understanding. While we want to strive well to understand who our great God is and what he has revealed to us, a PhD in biblical interpretation or philosophy is not necessary for us to ably give an account of the hope that is within us. I want to suggest 10 tenets to keep in mind as you begin to have apologetic conversations with unbelieving friends and neighbors. These 10 tenets flow from biblical truth, and find agreement with what many have said in the Reformed tradition.
1. The faith that we are defending must begin with, and necessarily include, the triune God—Father, Son, and Holy Spirit—who, as God, condescends to create and redeem.
In saying we "must begin with" the triune God, we are not arguing that all apologetic discussions must start with an explanation of the triune God; rather, we must never assume that we are defending anything but what God himself—as Father, Son, and Holy Spirit—has accomplished in creation and redemption. Generic theism is no part of the Christian faith.
2. God's covenantal revelation is authoritative by virtue of what it is, and any covenantal, Christian apologetic will necessarily stand on and utilize that authority in order to defend Christianity.
We cannot begin our discussion with the assumption that the intellectual, moral, or conversational ground on which we and the unbeliever are standing is the same. The very reason there is a debate between us is that our respective authorities are in conflict. The unbeliever will stand on something in order to debate and discuss, and we will stand on Scripture (which finds its authority inextricably tied to God). We do not seek to establish the authority of God's Word, only explain it.
3. It is the truth of God's revelation, together with the work of the Holy Spirit, that brings about a covenantal change from one who is in Adam to one who is in Christ.
We are encouraged by this third tenet to communicate the truth of God because it is this truth that the Holy Spirit uses to change hearts. What a privilege it is that we, as believers, can be instruments of the Holy Spirit as he changes minds and hearts!
4. Man (male and female) as image of God is in covenant with the triune God for eternity.
This point can hardly be overstated. Since all men and women are images of God, they are responsible to him for everything they are, do, and think. Every person lives coram Deo—that is, before the face of God. All are obligated to obey him because he is their creator and sustainer.
5. All people know the true God, and that knowledge entails covenantal obligations.
Scripture is clear that all people know God; not simply a feeling that there is something bigger out there, but the true and living God of Scripture (Rom. 1:18–20). This knowledge comes not through some inferential process, but because God reveals himself in all of creation that renders all people everywhere responsible to respond rightly to who he is.
6. Those who are and remain in Adam suppress the truth that they know. Those who are in Christ see the truth for what it is.
Though God has clearly revealed himself, because of sin we seek to suppress this knowledge of God. In Adam, we deceive ourselves from the truth, and instead build up falsehood to avoid God.
7. There is an absolute, covenantal antithesis between Christian theism and any other, opposing position. Thus, Christianity is true and anything opposing it is false.
When we get down to any system of belief, there are only really two foundations: either submission to Christ and affirmation of the truth of what God says, or we oppose him and try to "create" another world of our own making. No matter what kind of opposition we face, we know that it cannot make sense of the real world since God has created and maintains all of reality. Denial of Christ entails submitting to some sort of falsehood.
8. Suppression of the truth, like the depravity of sin, is total but not absolute. Thus, every unbelieving position will necessarily have within it ideas, concepts, notions, and the like that it has taken and wrenched from their true, Christian context.
When someone suppresses the truth in unrighteousness, that suppression is total. There is nothing that he knows, thinks, and does that is not affected by it. But it is not absolute. He cannot completely eradicate or submerge the knowledge of God that is always his and always being given by God. Thus, there will be aspects of the truth of the knowledge of God that surface in those who are in Adam. So even as an unbeliever may be able to know true things about the world around them, their knowledge is ultimately borrowed and serves to further condemn them.
9. The true, covenantal knowledge of God in man, together with God's universal mercy, allows for persuasion in apologetics.
How can we commend the faith to unbelievers if they will suppress God wherever they can? First, when we speak God's truth to them, it "gets through" and "connects" to that knowledge that God is continually giving to them. Second, because of his universal mercy, God will sometimes restrain sin and depravity that might hinder our conversations, so that his Word might be planted in good soil.
10. Every fact and experience is what it is by virtue of the covenantal all-controlling plan and purpose of God.
The facts of the world display God's glory (Ps. 19:1ff; Rom. 1:20). To take those facts for selfish use is to twist them and pervert them. This is culpable rebellion against God, and it takes place as those in Adam "live and move and have [their] being" in the triune God. So in order for someone to understand one fact properly, that fact needs to be seen in the context of God's plan and purposes.
This piece is adapted from K. Scott Oliphint, Covenantal Apologetics: Principles & Practice in Defense of Our Faith (Wheaton, IL: Crossway, 2013), 47–55. Used with permission of the publisher.