You have no self-confidence, but you are a man under authority, and you have authority; and this should be evident and obvious.
Martyn Lloyd-Jones
Jesus taught “thus says the Lord” whereas the Pharisees taught “he said..., she said...”
And they were astonished at his teaching, for he taught them as one who had authority, and not as the scribes.
—Mark 1:22
The message of Jesus is never maybe; it is always an emphatic yes. By implication, we too mustn't speculate in our teaching if we desire to deliver Christ's message.
Such authority was not a new thing
Thus says the Lord... (appears 268 times in the Old Testament)
The word of the Lord came to... (appears 101 times in the Old Testament)
This call of confident proclamation is affirmed by observing that this is not something particular to Jesus. All the prophets spoke in this way before Jesus, and all the apostles likewise taught with authority after him.
What was their secret? The answer is simple: if we want to teach with God’s authority, we need to accurately teach God’s word. So long as we do not force our ideas on the text, but let the text teach us, we will be delivering its message and not our own. And when we teach the Bible's message, the authority of our teaching is unbounded.
This truth cuts two ways. On the one hand, if we unequivocally declare a misinterpretation of the Bible, or confidently air our own opinions on something not made clear in the scriptures, then we should be in great fear. For the Lord is not pleased. On the other hand, “perhaps” and “maybe” have no place in biblical teaching either—because it is not about your ideas! Simply put, don't say it in a sermon if the Bible doesn't teach it. Don't use up your small group Bible study's precious time with postulating.* Instead, declare confidently what the word does in fact teach.
We, like Jesus, want to teach with God's authority. And the way to do so is to teach God's word.
The temptation to teach without authority
Given these things, why are we inclined to mingle in our opinions? Oftentimes it is our pride. We think we are smart and have something to say. Or perhaps we feel that the Bible is an old hat—that it is boring.
And why do we struggle with declaring Truth with absolute confidence? One reason is that teaching without authority is more comfortable. I can be wrong and it is no big deal! Also, suggesting that someone consider whether they are wrong in their lifestyle choices is far more acceptable than plainly telling them they are in sin. Finally, sometimes we don't have confidence in the meaning of the text because we haven't spent enough time to study it well.**
Whether for these reasons or others, God calls us to leave such ways behind and to teach with authority, which we do by teaching his unadulterated word. Indeed, if we live for God's glory and not for the praise of man, and if we can confidently get at the main point of a text, then we too will convey that text with authority.
For we are not, like so many, peddlers of God’s word, but as men of sincerity, as commissioned by God, in the sight of God we speak in Christ.
—2 Corinthians 2:17
I charge you in the presence of God and of Christ Jesus, who is to judge the living and the dead, and by his appearing and his kingdom: preach the word...
—2 Timothy 4:1-2
* Certainly there are times to use a small group Bible study to teach people how to study a text so that they can learn to feed themselves spiritually. In such cases, showing them how to ask good questions and wonder about the meaning has its place. Even so, the goal would not be to see who in the group comes up with the best idea of how to interpret the passage, but arriving at an understanding from further observation of the text at hand and the scriptures as a whole. (More on this on a later step.)
** What should you do when you have studied a text thoroughly and arrived at conclusions, but by no means have absolute confidence that all of your conclusions are correct? This demands wisdom and at least a couple considerations. (1) Are we dealing with a doctrine which is absolutely clear elsewhere in the Bible? If so, lean on those clearer texts in conjunction with the passage of focus in the lesson. (2) Can the uncertain conclusion be touched on for just a minute and left without your explanation of the main point and passage as a whole being harmed? If not, you should not teach this text.