Now, it is a disgraceful and dangerous thing for an infidel to hear a Christian, presumably giving the meaning of Holy Scripture, talking nonsense on these topics; and we should take all means to prevent such an embarrassing situation… the shame is not so much that an ignorant individual is derided, but that people outside the household of faith think our sacred writers held such opinions, and, to the great loss of those for whose salvation we toil, the writers of our Scriptures are criticized and rejected as unlearned men.Augustine, St On the Literal Meaning of Genesis, Taylor, J. H. (trans.), New
York: Newman Press (1982), p. 42.
I don't think that someone must be intelligent in order to be anointed by God or to be effective for His Kingdom. However, I have come to believe that if one is called and anointed by God to preach and teach His Word, that they should, as a good steward, be involved in academic study, to make sure they aren't misrepresenting God in their teaching, so they don't bring shame upon themselves, or worse, upon the Body of Christ which they represent. This is precisely what Augustine is getting at here.
I've talked to many people who have concerns about the academic study of theology, and for good reasons. They often say that people go into it with a desire to know God more, and that seminary kills their faith. Others point out that academic theologians often spend all their time splitting hairs theologically and ignoring the Great Commission to go and make disciples of all nations. What I have found is that if one goes to seminary as a born again Christian who has had a personal encounter with God, those things will not be a problem, but rather the study will deepen and strengthen one's faith.
Neglecting theological study in exchange for pragmatism is dangerous because anyone can just come along with little or no training, call themselves a pastor, and start preaching to whoever will listen. Sometimes this can be harmless, but many times it can be, and has been, outright dangerous and destructive. If one doesn't have a basic understanding of how to properly interpret and apply the scriptures, there is a much greater chance that they will teach things which are not the intended message of God in His Word, and this has surely led to much aberrant teaching throughout the history of the Christianity - people who didn't know what they were talking about taught things in God's name, which were not really God's true intention or desire. So, theological training is important.
Personally, the biggest impact my theological studies have had on me is that I feel I have gained a broader perspective. In regard to doctrines and theological issues, rather than just being exposed to one line of thinking, and repeating that which I was told by others, without really looking into things myself. I haven't really changed many of my theological convictions; if anything, I feel that my understanding of those theological positions has been expanded and deepened, and I have a better grasp on the big picture of WHY people believe the things they do, and what the background to different positions are. More than simply "is this opinion right or wrong", it comes down more to "HOW do people come to the conclusions they come to? What is the line of thinking that leads them there?"
Studying theology doesn't necessarily need to be done in a seminary or Bible College - I read about Martin Lloyd Jones that he was completely self-taught, yet he was one of the most influential theologians of the past hundred years. However one goes about doing it, studying theology and learning how to "rightly divide the Word of Truth", it is something which should be a priority to those who teach God's Word. We should have an idea what we are talking about.