To begin, we’ve said before that apologetics is a conflict in worldviews. To break that out a little more we find that worldview differences stem from appeals to different sources of final authority. As Christians we hold that God speaking in his word is the highest authority. Rationalists hold that human reason is the highest authority. Ironically skeptics appeal to the same authority. An empiricist will finally appeal to what can be sensed and experienced. A Muslim will appeal to the Koran; a Jew to the Tanakh. So what we need to see is that apologetics is not just I believe something and this person believes something else but that we believe it on the basis of entirely different belief structures. From a Christian perspective John Frame helps to outline this:
We trust Jesus Christ as a matter of eternal life or death. We trust his wisdom beyond all other wisdom. We trust his promises above all others. He calls us to give him all our loyalty and not allow any other loyalty to compete with him (Deut. 6:4ff; Matt. 6:24; 12:30; John 14:6; Acts 4:12). We obey his law, even when it conflicts with lesser laws (Acts 5:29). Since we believe him more certainly than we believe anything else, he (and hence his Word) is the very criterion, the ultimate standard of trust. What higher standard could there possibly be? What standard is more authoritative? What standard is more clearly known to us (see Rom. 1:19-21)? What authority ultimately validates all other authorities?The above quote helps to outline the conflict with unbelief. No unbeliever can accept our standard for truth and knowledge. To do so would be to adopt our worldview and accept the invalidation of their own. So while the Christian appeals to Christ speaking in Scripture the unbeliever appeals to his own authority and standard of truth. The reason that this point is so fundamental for apologetics is that we cannot prove Christianity if we accept a different final authority. Rationalism, skepticism, empiricism, Islam, and Judaism do and must reject Christianity on the basis of their own worldview and authority structures. Christianity cannot be true if human reason, sense experience, or Allah are the ultimate authority. So the goal of apologetics remains to move someone from an appeal to a non-Christian authority to subjecting themselves to the Lord Jesus Christ in all things.
The apostle Paul demonstrates this point for us:
For the wrath of God is revealed from heaven against all ungodliness and unrighteousness of men, who by their unrighteousness suppress the truth. For what can be known about God is plain to them, because God has shown it to them. For his invisible attributes, namely, his eternal power and divine nature, have been clearly perceived, ever since the creation of the world, in the things that have been made. So they are without excuse. For although they knew God, they did not honor him as God or give thanks to him, but they became futile in their thinking, and their foolish hearts were darkened. Claiming to be wise, they became fools, and exchanged the glory of the immortal God for images resembling mortal man and birds and animals and creeping things.In this passage Paul outlines the problem of unbelief for us. We’re just going to outline a few things from this passage though we’ll come back to it in later posts. The chief point that Paul makes is that what is to be known about God is plain to all people because God has made it plain to them. This revelation is more than just God’s existence but is a revelation of something of his person and character. Because of this revelation all people are without excuse in the face of God’s wrath. God’s wrath is revealed from heaven against all ungodliness and unrighteousness of those who suppress the truth of the knowledge of God. The way that they do this is by exchanging the glory of God for images resembling created things, by exchanging the truth of God for a lie, and by worshipping the creature rather than the Creator. All of this is to say that they have exchanged the obedience that they owe to the sovereign Lord who authoritatively reveals himself and his will for other gods, or other standards of authority. Following after Adam in the Garden, they have chosen to listen to serpents, devils, and created things rather than to the divine command.
Therefore God gave them up in the lusts of their hearts to impurity, to the dishonoring of their bodies among themselves, because they exchanged the truth about God for a lie and worshiped and served the creature rather than the Creator, who is blessed forever! Amen. (Rom. 1:18-25)
This passage helps us to see the necessity of calling someone to move from placing themselves under their own chosen authority to submitting to the Triune God. Cornelius Van Til was fond of saying that we can choose theonomy (God rule) or autonomy (self rule) with nothing in between. We may obey and follow God’s revelation or we may exchange it for worshipping something that he has created. There is no third option. So as Christians commanded to engage in apologetics we call unbelievers to submit to Jesus Christ. In future posts we’re going to try to unpack how we do this.
 John Frame, Apologetics to the Glory of God: An Introduction (Phillipsburg: P&R Publishing, 1994) 6-7.