I have to agree that his first premise is valid, but I don't agree with the second premise and thus, his conclusion. I don't think that anyone can be "argued" into the Kingdom. For example, knowing that someone exists is different from wanting a loving relationship with them. Someone can believe that the Christian God exists, yet not want to have a personal relationship with Him. That person can recognize that the evidence points toward the Resurrection being a historical event, but not want to dedicate their life to that fact. A belief that is different from a belief in.
A belief that means you know that something is true. A belief in is a life-commitment to that truth (a conscious choice to change your actions to be consistent with that truth). See Psychology Class Series for more on this.
Having said that, a belief in something requires a belief that that something exists. If someone does not believe that something is true, why would they commit their life to it?
Apologetics is important because it helps people to take the first large step into the Kingdom. For many people, an apologetic approach is not necessary (they may not have philosophical, historical or scientific questions). They may simply have never understood the Gospel. In this case, no, we don't need to waste our time with philosophy. We don't want to create a stumbling block where one does not exist or is not realized by the person himself (1 Corithians 10:32-33).
I have to admit that I have focused so finely on the arguments that I fear I have created stumbling blocks where they weren't before. When to use apologetics and when to simply present the Gospel (or both) is something that I have to learn. I believe the caller above had a good point in showing a possible extreme, but he must recognize, though, that his side is also an extreme. Greg Koukl's book Tactics (My Review) is a great resource to start to help determine when to use which approach with a nonbeliever.
This reminds me of the value of the different parts of the Body of Christ. Granted, all Christians are called to "be prepared to give an answer to everyone who asks you to give the reason for the hope that you have" (1 Peter 3:15), but there are some who have deeply studied specific challenges and their answers. Christians should never think of one "gift" as less valuable than another (1 Corinthians 12:24-26) because some day, they may need to swallow their pride and refer someone to a Christian whom God has given the answer to the question being asked of them.
As mentioned in the Psychology Class Series, emotions (the heart) is key to the acceptance or rejection of a belief. The Holy Spirit is who works on the heart of people to bring them to Christ. The Holy Spirit prepares the emotions (heart) to accept the evidence. Christ commanded his disciples to go make disciples. The Christian's duty in evangelism is to provide the evidence to the person, so that the emotions (the heart that the Holy Spirit has been working on) will accept it- thus changing a life. Those whom the Holy Spirit has been working on are drawn to Christ, but may need an intellectual reason to accept Him. Apologists can provide that intellectual reason. We need to "be prepared to give an answer to everyone who asks you to give the reason for the hope that you have".
Near the beginning of this post, I stated that no one can be argued into the Kingdom. The reason for this lies in the above paragraph. If the Holy Spirit has not prepared the emotions (heart) to accept the evidence, no number of arguments will convince them. They are emotionally attached to a non-Christian idea, and will satisfy themselves with all sorts of rationalizations and absurd philosophies to avoid acceptance.
As the Church, we need to learn to recognize our role in the Great Commission. It is not to convert; it is be a witness- provide evidence from experience, nature, and philosophy. We also need to recognize the role of the Holy Spirit. It is to soften the heart to allow for the recognition of and commitment to The Truth.
I remember my frustration when in my "earlier" years as an "apologist". I would always think that I've got the Truth and impenetrable arguments to support it. When one argument didn't cause a conversion, I would arrogantly whip out another (unwittingly, this probably cause more stumbling blocks). When someone still didn't accept it, it caused much frustration for me. I just didn't understand how or why someone just couldn't get it. When that happened, lots of ad-hominem attacks were having a party in the back of my head and were attempting to dance right out my mouth.
When I finally recognized this balance of duties with regard to The Great Commission, my frustration with people who "just don't get it" went down considerably. I had to swallow my pride. I am not that great. The salvation another a non-believer is not because of me. It is because of the Holy Spirit who worked in the life of the non-believer and myself (which is a result of the Holy Spirit working on my heart, which is the result of the Holy Spirit working on the heart of another, etc...). There is no need for me to get so frustrated or be arrogant. If an argument that I present helps a person come to Christ, I thank God that He allowed me to be an instrument in His orchestra. I am still in the process of being sanctified by Him, and at times, I will be out of tune and hit wrong notes. Because my choice is to worship Him with all my heart, soul, and mind, He can still use me to be an ambassador, while He prepares me for eternity with Him.
Here is another great post on this topic by Josh Fults: Can You Argue Someone Into Believing In God?