How important are good reasoning skills for a Christian? On the one hand, there's nothing more cringeworthy than watching Christians run combatively into the arena with atheists, holding high the 1 Corinthians 4:10 banner: "Fool for Christ!" It makes me desperately wish that a friend would take them aside and suggest that apologetics may not be their calling. Intellectual slaughter is not the kind of martyrdom that glorifies God the most.
On the other hand, Paul did say that "knowledge makes arrogant, but love edifies (1 Corinthians 8:1)," "For the kingdom of God does not consist in words but in power (1 Corinthians 4:20)," "Where is the wise man? Where is the scribe? Where is the debater of this age? Has not God made foolish the wisdom of the world? 1 Corinthians 1:20)" and "When I came to you, brethren, I did not come with superiority of speech or of wisdom, proclaiming to you the testimony of God. For I determined to know nothing among you except Jesus Christ, and Him crucified (1 Corinthians 2:1-2)."
So is ignorance the key to spiritual power then? No, but an awareness of the limitations of knowledge, eloquence, and persuasiveness is. One act of divine love in a human heart has more power to break down walls than the most masterful apologetics.
Paul is not downplaying knowledge and education--he's just putting it in perspective. Keep in mind that Paul was the greatest theologian of all time, and he wrote the above verses to the divisive Corinthian church, who had been "enriched in [Christ], in all speech and all knowledge." (1 Corinthians 1:5) So they weren't dummies either. They just trusted too much in their wisdom.
It is sobering to read the Amazon reviews of C. S. Lewis's Mere Christianity, considered to be the greatest work of apologetics of all time. Most of the Christians loved it, but the atheists gave it one-star reviews. As the back of his books so aptly says: "He is the ideal persuader of the half-convinced." But logic and eloquent rhetoric has no power to reach those who have set their minds against Christianity. It just doesn't work that way. "For since in the wisdom of God the world through its wisdom did not come to know God, God was well-pleased through the foolishness of the message preached to save those who believe." (1 Corinthians 1:21) Can it be more clear?
We should think of knowledge in the same way as goodness, in the sense that it is only when we try our very best to be good--and fail--that we are ready to understand and appreciate the saving power of faith. Likewise, after we apply ourselves to understand the things of God, sharpening our minds and preparing ourselves in every way, we have to learn that it's a worthless tool out of the Master's hand. He alone can save souls and build up his kingdom. We have to see the limits to both our own goodness and our knowledge before we can share in God's power.
The thing is, some of the people who enter the fray with unbelievers come with neither eloquence and wisdom or power and love. I've seen them mock atheists while making a mockery of Christ. We all make mistakes in our choice of words (some of mine are immortalized on the Internet for all the world to see), so I don't want to come down too hard on anyone. But why be relentless in our efforts to strengthen someone else's atheism? The Physician's Creed can be equally well applied to us: "First do no harm."
I want to end with a quote from Charles Spurgeon that I already used in my previous post, but it's worth repeating: "What a barrister can do in advocating the cause of his client, you and I should surely be able to do in the cause of God. The bar must not be allowed to excel the pulpit. We will be as expert in intellectual arms as any man [or woman], be they who they may, God helping us." With God's help, why should any argument put forth by an unbeliever intimidate us?
But if we are intimidated, we can serve God in some other capacity. Spurgeon also said: "A certain preacher, whose sermons converted men by scores, received a revelation from heaven that not one of the conversions was owing to his talents or eloquence, but all to the prayers of an illiterate lay brother, who sat on the pulpit steps, pleading all the time for the success of the sermon." Let's never underestimate the power of prayer.
I realize that I'm preaching to the choir here (or maybe I'm just venting), but let's not take Paul's words about being "fools for Christ" too literally. We do have God's glory to uphold.