"Secular" Reason?
I have written many times about the coexistence of faith and reason (the most recent is "Is Faith Logical or Emotional?"), so I'm not going to rehash that information here. However, I would like to point out that the author undermines their own argument by implying that "secular" reason and methods can't be trusted. If we are to follow and understand the author's argument, we must first accept the basic laws of logic. If those are not reliable, then neither is any argument made that follows the rules of logical reasoning reliable.
Most apologists (specifically named by the author: William Lane Craig and Alvin Plantinga) use the laws of logic when they reason as they defend the truth of Christianity. If the laws of logic are not reliable, then not only does any rational argument for Christianity's truth fail (1 Corinthians 15 comes to mind), but no argument for the truth of anything is reliable- everything is believed by 100% blind faith. If everything is believed by blind faith (and by "everything", I mean all truth claims- including conflicting ones such as that "Islam is true" and "Christianity is true"), then all we have are mere opinions (see Opinion vs. Truth-Claim).
If all that we have are merely opinions, then we have effectively placed Christianity in the same epistemic vacuum that atheism is in- reason is gone, knowledge is gone, value is gone, morality is gone, purpose is gone. I expand quite a bit on these in my post The Fear of Atheism. What I have written in that post applies equally to the type of blind-faith Christianity that the author of "Christianity's New F-Word" is proposing we should live by.
Assuming What's True First?
The best way that I can explain the issue with this is to give an example. Let's say that a friend of ours is a Muslim. They assume the reliability of the Qu'ran and the truth of their worldview- all evidence that they come across must be interpreted with through that lens; no evidence can overturn the truth of Islam or the reliability of the Qu'ran. Anything and everything that we say (whether it is evidence-based or emotion-based) is interpreted in light of those two commitments. They believe that even though there may appear to be a contradiction between their beliefs and what we are saying, there either isn't (because we are wrong- because the Qu'ran says we're wrong), or that Christians are using "secular" reasoning that is not of Allah. Both the Muslim and the Christian believe the other to be unreasonable and defiantly rejecting the true God (or Allah).
Now, in your mind, change the roles of the Christian and the Muslim. This new scenario is exactly what the author of "Christianity's New F-Word" is placing the Christian in. In neither situation does one have anything to show that their view is actually true to the other. Some Christians say that the Holy Spirit will show the Muslim in this case. But doesn't the Muslim believe something remotely similar? We certainly can't use what actually happens (Christian converts to Islam or Muslim converts to Christianity) to know which is true, because both do happen. On the test-less, a-rational model proposed, we are doing the same as relying on a Magic 8 Ball to tell us which worldview is correct...and please don't appeal to a subjective feeling- Mormons appeal to a "burning in the bosom" too, yet Christians don't recognize Mormonism as true.
If the Muslim assumes their worldview true before anything else, they run the risk of being wrong. If the Christian assumes their worldview true before anything else, they run the risk of being wrong also. "If Christ has not been raised, we are still dead in our sins!" It doesn't matter how sincerely, blindly, or steadfastly we believed it; if Christ dead, so are we. Paul makes that very clear. If we are wrong, we need to know what is right. If we assume, first, that Christ has been raised but he really hasn't, then how can we ever expect to find the truth? If Muhammad was not the last prophet of Allah, yet someone believes it regardless of evidence to the contrary, how will they find the Truth? How are we to know that some spirit that imitates "feelings" of the Holy Spirit will not lead the Muslim to Hinduism?
Paul continues to say that Christians should be pitied among men if we have believed what is not true of Christ. He does not understand "blind faith" to be the crux of Christianity; he understands Christ's resurrection to be. If Christianity is not testable or we discourage testing, we are speaking against Paul, and we are merely providing an opinion of what we "feel" is true- hardly a reason to believe anything!
Line-For-Line Critiques
The author also took issue with Christian apologists addressing challenges in detail. However, to be fair, it did not seem that the detail was the author's issue, rather it was the readiness and eagerness to do so that seemed problematic. The author believes that the act of challenging and addressing arguments against Christianity has become the focus of apologists' lives rather than Christ. The author makes the case that such detailed addressing of challenges is actually counter-productive by appealing to Kierkegaard's refusal to engage in these detailed critiques.
One thing that needs to be gotten out of the way very quickly is that the author cannot rely solely upon Kierkegaard's decisions to build a case for what Christians should do, unless they wish to place Kierkegaard's authority on the level of infallibility with Scripture. I don't think that the author actually does, so based on that, there is no case being actually made, just an assertion (or opinion, if you followed the rest of this post) being offered.
I do want to stop for a moment and grant the author the physical observation. Many apologists are very ready and eager to address challenges to the Christian faith. Many apologists do interact at the highest level of academic prowess. And, yes, those can take the place of God in our lives...if we allow them to. This is one of the many dangers that we face when we are carrying out the Great Commission.
We have to recognize that different members of the Body of Christ bring different gifts and talents to the table. Each one will be able to address unbelievers who are in different situations and currently don't accept Christ for different reasons. When I have spoken to and read the top apologists, they are not concerned with their own ego or making Christianity a dry topic of heated discussion, but rather they want to address challenges that unbelievers authentically struggle with. There are also challenges that Christians authentically struggle with. When philosophers and theologians can help people (believers and unbelievers) through difficult challenges and bring them either into the Kingdom or closer to God, it brings God glory.
Conclusion
Paul cautioned the Church not to think that the Body can do without certain parts. We all have purposes- purposes that others do not necessarily have. God gave us our gifts and talents to carry out those purposes, and gave others gift and talents to carry out their purposes. All these purposes bring God glory. Most importantly, we need to build each other up, not tear each other down. Just because we can't see some direct effect of a ministry does not mean that there is no effect or that the ministry is not necessary; it especially does not give us a right to tear them down.
Finally, since we each do have some talents and gifts, but not others, we need to use the talents and gifts that we are given for the purposes that they are intended. People work against the Kingdom all the time by doing things they are not called to do, and doing them very poorly. I'm not saying that all apologists are called to be apologists or that they do it well; I'm saying that we all need to be very aware of our gifts and recognize when we are trying to do someone else's job at the expense of our own. Once again, no one is not needed. Everyone is needed. The key is to find where you are called to be used, and allowing the rest of the Body parts to perform their function as you do yours- apologists included! :)
Every person (including the unbeliever) is created unique and cannot be painted with a broad brush. The presuppositional approach to evangelism that the author clearly prefers does not appeal to all unbelievers, and we do want to reach these people. Therefore, we need to leave room for other approaches as well. If one of the others is not your preferred method (because you don't like it or have not been effective with it), then don't use it; but do not deride a fellow Christian, who is just as passionate for the truth of Christ's resurrection as you are, for using it to be effective and do enjoy it- to the glory of God.
"I have found that the more I reflect philosophically on the attributes of God the more overwhelmed I become at his greatness and the more excited I become about Bible doctrine. Whereas easy appeals to mystery prematurely shut off reflection about God, rigorous and earnest effort to understand him is richly rewarded with deeper appreciation of who he is, more confidence in his reality and care, and a more intelligent and profound worship of his person."- William Lane Craig