Pastors don’t know everything. In fact, an important part of shepherding God’s people is having the humility to take the time to search for the right answer instead of quickly and carelessly deploying the wrong one.
But it’s one thing to tell your congregation “I don’t know.” It’s another entirely to stand before them and say “I can’t know, and neither can you. But you should still listen to me.” That’s the hazardous message emanating from too many pulpits today—nobody knows what God’s Word really means.
I preach the Word of God because it is understandable. God revealed His Word in such a way that it can be comprehended with clarity (cf. Psalm 119:105, 130). If He had not done so, the Bible would no longer serve as an objective standard for life, since it could not be understood in a straightforward sense. Yet, because He has revealed His Word in a way that is universally comprehensible, all men are accountable to it.
If the clarity of Scripture is denied, the certainty of any biblical doctrine must also be rejected, since we can no longer be sure that the Bible actually means what it says. Once doctrinal certainty grounded in biblical authority is dismissed, personal convictions must also be discarded, since they no longer have any firm foundation. And if personal convictions disappear, spiritual community will also vanish, since true fellowship necessarily begins with shared values and convictions.
A healthy church is one that is motivated by a common affection for God and His Word, and one that really knows what it is to love one another. That affection, both for God and for others, arises out of the confidence that the Bible is true, that it is absolute, and that it can be understood.
Scripture is clear. Deny that simple fact and you forfeit all confidence and conviction. No wonder evangelicals who have drifted away from the centrality of Scripture seem to lack certainty and clarity about anything. Careful exegesis and doctrinal precision are inevitable casualties of postmodern uncertainty, too. Consider this shocking comment from a supposedly conservative minister:
If there is a foundation in Christian theology, and I believe that there must be, then it is not found in the Church, Scripture, tradition or culture. . . . Theology must be a humble human attempt to “hear him”—never about rational approaches to texts. 
That is an amazing statement. It is ludicrous. How can we truly “hear him,” meaning God, unless we go to the place He has spoken—His Word? The only way I can ever be certain about anything is to approach every biblical text with a careful, rational, discerning mind to hear and understand accurately what God is saying. Take that away and what basis is there for certainty about any truth?
One of the most popular writers in the Emerging Church movement—which embodied postmodern skepticism and relativism—succinctly summarized his mindset, saying, “Certainty is overrated.”  In one of his books, he writes, “I have gone out of my way to be provocative, mischievous, and unclear, reflecting my belief that clarity is sometimes overrated, and that shock, obscurity, playfulness, and intrigue (carefully articulated) often stimulate more thought than clarity.” 
The wife of another leading pastor from the Emerging trend celebrated her uncertainty, saying, “I grew up thinking that we’ve figured out the Bible, that we knew what it means. Now I have no idea what most of it means. And yet I feel like life is big again—like life used to be black and white, and now it’s in color.” 
And so we often hear of a new hermeneutic, grossly mislabeled as the “hermeneutics of humility,” which essentially says, “I’m far too humble to say that I know what the Bible means, and anybody who claims to know what it means is arrogant.”
But what’s more arrogant than claiming that God has not spoken clearly enough for us to understand?
When I preach, the response that always pleases me most is, “The message was clear.” Clarity is critical and basic. Ambiguity is deadly and produces nothing. People who think the truth itself is ambiguous don’t know where to turn for salvation. They can’t be sanctified. They don’t find comfort. We get nothing from ambiguity except confusion. Clarity is the desired result of a good understanding of the biblical text. If a preacher is not clear to his hearers, it is likely because he is not yet clear in his own mind. That means more diligent study is required.
When I started in ministry, I committed myself to expository preaching—just explaining the Bible—because I knew there was nothing I could say that was anywhere near as important as what God had to say. The real goal of my teaching has always been to keep my own opinions out of it as much as possible—to get the meaning of the passage right and to make it clear to my hearers. Pastors need to remember from the very outset that when they go into a pulpit, they are there to explain the Word of the living God with clarity and precision, not to impress people with their own cleverness or amuse them with human opinions.
The Word of God is clear, and when I explain it accurately to my people, they understand it. That understanding is the first and most essential point of expositional preaching, because people cannot believe or obey truth they don’t understand, thus building their lives on the wisdom that comes from above. A clear understanding of God’s Word forms the convictions that shape our lives and leads to deep affection for divine truth (Psalm 119:129–31; 19:10).
Source: John MacArthur | Grace To You