Here are some great thoughts from William Lane Craig, one of the leading Christian philosphers and apologists. Here, he explains the difference between how we as believers in Christ know Christianity is true versus how we show others that it is true. The difference can help you in sharing your faith and preaching the gospel. One other thing to notice is that even a guy like Dr. Craig struggles with doubt, and it’s when his spiritual life is weak: “The Christian who is not filled with the Spirit may often be wracked with doubts concerning his faith. I can testify personally that my intellectual doubts seem most poignant when I am in a carnal position.” Read on to see his thoughts on these things…
We’ve seen that in answering the question “How do I know Christianity if true?” we must make a distinction between knowing that it is true and showing that it is true. We know Christianity is true primarily by the self-authenticating witness of God’s Spirit. We show Christianity is true by presenting good arguments for its central tenets.
What, then, should be our approach in using apologetics with an unbeliever? It should be something like this:
My friend, I know Christianity is true because God’s Spirit lives in me and assures me that it is true. And you can know that it is true, too, because God is knocking at the door of your heart, telling you the same thing. If you are sincerely seeking God, then God will give you assurance that the gospel is true. Now, to try to show you it’s true, I’ll share with you some arguments and evidence that I really find convincing. But, should my arguments seem weak and unconvincing to you, that’s my fault, not God’s. It only shows that I’m a poor apologist, God still loves you and holds you accountable. I’ll do my best to present good arguments to you. But ultimately you have to deal, not with arguments, but with God himself.”
The foregoing discussion has profound practical application both in our Christian walk and in our evangelism. With regard to our Christian walk, it helps us to have a proper assurance of the truth of our faith. A student once remarked to me after class, ‘I find this view so liberating!’ He had struggled for some time to sort out the relationship between faith and reason, but without success. Christians often fall into the extremes or fideism or theological rationalism. But the view just expounded enables us to hold to a rational faith which is supported by argument and evidence without our making that argument and evidence the foundation of our faith. It is tremendously liberating to be able to show an unbeliever that our faith is true without being dependant upon the vagaries or argument and evidence for the assurance that our faith is true; at the same time we know confidently and without embarrassment that our faith is true, as can the unbeliever as well, without our falling into relative subjectivism.
This view also underlines the vital importance of cultivating the ministry of the Holy Spirit in our lives. For though all Christians are indwelt by the Spirit, not are all filled with the Spirit. The New Testament teaches that we can grieve the Holy Spirit by sin (Eph. 4:30) and quench the Spirit by repressing His working in our lives (1 Thess. 5:19). The Christian who is not filled with the Spirit may often be wracked with doubts concerning his faith. I can testify personally that my intellectual doubts seem most poignant when I am in a carnal position. But when a Christian is walking in the Spirit, then, although his intellectual questions may remain, he can live with those questions, without their robbing his faith of its vitality. As the source of our assurance that our faith is true, the Holy Spirit’s ministry in our lives needs to be cultivated by spiritual activities that help us to walk close to God, such as Bible Study, prayer, devotional reading, inspirational music, evangelism, and Spirit-filled worship.
In evangelism, too, this view enables us to give the unbeliever rational arguments and evidence for the truth of the gospel, instead of challenging him to ‘just have faith.’ I have met many non-Christians who came from conservative Christian backgrounds and who were turned off to the gospel by having their honest questions squelched and being told to just believe. By contrast, I recently received the following note from a Canadian student with whom I had chatted after one of my lectures:
I wish to thank you for speaking with me and for putting time into your busy life in order to converse with a second-year university student. I also with to thank you for never once bringing the word faith into the conversation. I’ve always felt that as soon as the word is brought up as an argument, the conversation can no longer continue, as it is an inarguable point. You were able to intelligently debate using logical points without resorting to the use of the informal logical fallacies. In return, I truly hope I was able to provide the same sort of intelligent debate.
At the same time, however, this view reminds us that unbelief is at the root a spiritual, not an intellectual, problem. Sometimes an unbeliever will throw up an intellectual smoke screen so that he can avoid personal, existential involvement with the gospel. In such a case, further argumentation may be futile and counterproductive, and we need to be sensitive to moments when apologetics is and is not appropriate. If we sense the unbeliever’s arguments and questions are not sincere, we may do better to simply break off the discussion and ask him, ‘If I answered that objection, would you then really be ready to become a Christian?’ Tell him lovingly and forthrightly that you think he is throwing up an intellectual smoke screen to keep him from confronting the real issue: his sin before god. Apologetics is thus most appropriate and effective when the unbeliever is spiritually pen and sincerely seeking to know the truth” (from Reasonable Faith, p. 58-59).