In my last post, I noted that God’s relationship to the universe could be analogized to an architect’s relationship to a building he designs. Just as the study of a house cannot give direct evidence of the architect, we can infer the existence of the architect from the design in the building even if we have no direct evidence that the architect exists. We are able to make this inference because by examining the building we can see where it is unlikely that all of the parts of the building could come together naturally without some intelligent design. While it may be possible to explain the existence of individual pieces of the building as the result of natural processes, it is difficult to imagine how they could all converge naturally in such a way as to present the finished product that we see.
Following that post, I felt it necessary to warn about the limits of analogizing in this way. Merely be examining the building, it is not possible to know much about the architect himself. An examination would reveal that the architect had knowledge about architecture and construction, about human needs, and about electrical, plumbing and heating/ventilation systems. There are other things that could be deduced about the architect from examining the building, but such an examination would not reveal much else about the architect as a person. It would not reveal his likes or dislikes. It would not reveal much about his background. It would not reveal anything about his hobbies or his personal life.
So it is with God and His relationship to the universe. By examining the nature of the universe with an understanding that a being that we call "God" is the creator of the universe, it is possible to see that God is extremely creative and powerful. It becomes apparent that he must be timeless (or so incredibly ancient that time has no real restrictions on him) and live beyond the four corners of the universe (else he could not have created it). Beyond these inferences, there is very little that we can discover about this god from merely studying the universe.
This is one of the weaknesses of arguing for the existence of God from the need for a creator of the universe. It seems as if many of the scientists who accept the idea that design is part of the nature of the universe are deists because studying the universe alone and relying solely upon that information for knowledge of God does not necessarily lead to the God of the Bible. Aristotle, for instance, looked at the universe and saw a creator, but his "unmoved mover" was an impersonal god. Atheist Antony Flew wisely saw that the evidence of design is strong using present scientific evidence, but adopted deism instead of Christianity because in his view all the evidence from design requires is a distant, uninvolved designer and not necessarily the God of Christianity.
In Mere Christianity, C.S. Lewis also noted that the information that was available about God from a study of the universe was, by the limited nature of the disclosure, not going to lead someone to the cross.
We have two bits of evidence about the [creator behind the universe]. One is the universe He has made. If we used that as our only clue, then I think we should have to conclude that He was a great artist (for the universe is a very beautiful place), but also that He is quite merciless and no friend to man (for the universe is a very dangerous and terrifying place).
Beyond these bits of information, Lewis is apparently of the opinion that not much more can be learned about God from the information gleaned from studying the universe.
Despite its limitation, making the case for a creator behind the universe is a useful tool to an evangelist. The goal of apologetics is to attack barriers to a proper belief in God. In that vein, I don’t view apologetics as the end of the evangelism process, but merely knocking down a wall which may be preventing a non-believer from responding to the Holy Spirit. To paraphrase Stand to Reason’s Greg Koukl, the goal of an apologist in speaking to a non-believer is to put a pebble in their shoe which will bother them about their belief systems. In the case of intelligent design, the recognition of the evidence for a designer in nature may lead someone to abandon atheism in favor of some form of deism. If they do this, they have not gone far enough for salvation, but they have taken a step closer to where they need to be.
Is it easier for an evangelist to approach a non-Christian theist or an atheist? I think it is undoubtedly true that the atheist is the more difficult to evangelize. At least the non-Christian theist has a sense of God (even if it is a mistaken belief) and probably is willing to acknowledge his feelings of guilt (for which the Gospel becomes "good news" since it grants complete forgiveness for the sins which generate the guilt). The atheist is a step behind the non-Christian theist on the road to Christ, and so the more difficult to evangelize.
However, if you are trying to rationally explain God to a skeptic, remember that the best way to lead them straight to Christianity (avoiding a sidestep into deism or other non-Christian theististic beliefs) is not the necessarily to lead them through the argument from design. Rather, the best way is to lead them through God’s self-disclosure about himself both in the moral law written in our hearts and in the revelation through the prophets and ultimately the person of the man/God Jesus Christ. In my quote of Lewis, above, he notes that there are two bits of evidence about the creator, only the first being what we can discover through nature. What is the second? According to Lewis:
The other bit of evidence is that Moral Law that He has put into our minds. And this is a better bit of evidence than the other, because it is inside information. You find out more about God from the Moral Law than from the universe in general just as you find out more about a man by listening to his conversation than by looking at a house he has built.
I would only add to this thought that the moral law does tell you more about God than the study of the universe, but the moral law written on our heart has also been corrupted to a certain extent, and so the best place to learn information about God is not studying the universe or studying the moral law, but rather studying the Bible. And it is this same Bible that should be the ultimate goal of any Christian to share with their skeptical neighbors.