It seems that books on apologetics have two benefits: if done well, they can equip Christians to address popular level critiques of Christianity. Additionally, they can reaffirm and strengthen a Christian's confidence in the rationality of the Christian faith. Norman Geisler and Frank Turek's I Don't Have Enough Faith to be an Atheist accomplishes both in a non-technical, even-handed, and clear manner.
Geisler and Turek's take an evidentialist approach to the truth of Christianity--faith, for them, rests upon evidence, and the preponderance of evidence is on the Christian's side. To get their, they establish the necessary foundations of the knowability of truth and the necessity for some belief (contra Hume and Kant). After that, they attempt a cumulative case for the existence of God, laying out the cosmological argument, arguments from (and for!) design, and an argument from the existence of a moral law. They then move into the specifics of Christianity itself: the possibility of miracles, the reliability of the New testament, and the deity of Jesus Christ.
In particular, their discussion of Intelligent Design (a topic the discussion of which has not been lacking at Mere O recently) was particularly helpful. Their argument that endeavours such as SETI that have been viewed as legitimate by the scientific community (Sagan, after all, was influential in its founding) rest upon identifying intelligent causation raises the plausibility of introducing intelligent causation as a viable, identifiable, scientific category. Additionally, their discussions of miracles and the reliability of the New Testament were particularly helpful.
However, they are at their worst when discussing the barriers to belief by atheists, typically mitigating the intellectual challenges to Christianity and emphasizing the volitional aspect to belief and disbelief. I remain uncomfortable attributing disbelief to a fundamental desire for autonomy, which Geisler and Turek clearly do. Such psychologizing is rather unhelpful in any discussion that touches on the truth of Christianity.
That said, I Don't Have Enough Faith to be an Atheist is eminently readable and extremely helpful. Their presentation is extremely clear. Though any single argument may not satisfy, the cumulative case they present is compelling. Even if one adopts evidentialism, Geisler and Turek make it clear that there is an immense amount of evidence for the truth of Christianity--certainly enough that any particular Christian is justified in holding their beliefs. Atheists may not be persuaded, but persuasion is a long process and I would hope a popular level book would not persuade. However, Christians who wish to begin to get a grasp (and this should be all Christians) of some of the intellectual foundations of the faith would be well advised to read Geisler and Turek's excellent book!
Matthew Lee Anderson is the Founder and Lead Writer of Mere Orthodoxy. He is the author of Earthen Vessels: Why Our Bodies Matter to our Faith and The End of Our Exploring: A Book about Questioning and the Confidence of Faith. Follow him on Twitter or on Facebook.