I think I see. Your last statement is exactly on point. In my assessment, you do not need a degree to answer such questions. Obviously, the more educated you are in various aspects of biblical studies, the more thorough your answers can be. But let's just take Rom 3:7 as an example. (By the way, I don't presume that I'll say anything not immediately obvious to you--just formally walking through that passage by way of example.)
- 5 But if our unrighteousness demonstrates the righteousness of God, what shall we say? The God who inflicts wrath is not unrighteous, is he? (I am speaking in human terms.) 6 Absolutely not! For otherwise how could God judge the world? 7 For if by my lie the truth of God enhances his glory, why am I still actually being judged as a sinner? 8 And why not say, “Let us do evil so that good may come of it”?—as some who slander us allege that we say. (Their condemnation is deserved!)
Seems obvious to me that verse 5 sets the tone and the basic problem Paul wants to address. God is righteous, and that righteous is demonstrated by juding our unrighteousness. No one, not your preacher, not a Muslim, not anybody, would disagree with that. Even people who think that God judging anyone would prove Him
unrighteous are actually conceding the point, because they're implicitly appealing to a deep notion of love and fairness and righteousness in itself, with the implicit but real assumption of the righteousness of those being judged. But if God judges, then we can't say
as judge He is unrighteous. The judgment demonstrates the righteousness.
And that sets up the problem and gives the solution. Verse 7 gives us a concrete illustation. If Paul were to lie about something, that would be unrighteous. God would judge him for it. That would demonstrate God's righteousness. Thus, Paul's lie gives occasion for God to enhance His glory. Of course, Paul doesn't actually say he does lie or that he is a liar. He could have said, "if my murder" or "if my adultery" or just "if my sin" more generally. This in no way proves that Paul is a liar or that Paul is telling any particular lie for the purpose of enhancing the gospel!
And that gets to the principle I'd highlight. One of them, anyway. Look at what the text says and not what you think it says. I teach a three week class from time to time on how to interpret the Bible. The first step is always on observation. I tell them not to interpret until they observe. Most people interpret before or as they observe. Don't do that. Just look at the actual text. What does it say? What are the relationships of the ideas? Here, we observe that Paul puts forward a general principle that God judging unrighteousness doesn't make Him unrighteous. Then we observe that Paul offers an example of a lie to be judged. And we observe Paul put that example in personal terms. Nowhere do we observe Paul actually trying to justify lying. In fact, just the opposite. Paul goes on to say (we observe) that those who justify sin because it enhances God's glory or justly (notice that word again! another observation) condemned.
You don't need a divinity degree to see that. You just need eyeballs and a willingness to read the text.
As far as systematically studying a book or concept, I think that's fine. But like you there's no necessity in it. Just take this exchange as an example. If somebody raises a question about a verse--Rom 3:7--we take it as an occasion to study that passage to see if the question is built on an appropriate interpretation. If not, and usually the answer is not, then what is the proper interpretation? And when you show that to someone and they refuse to listen, then frankly that isn't your problem. It demonstrates to you that the other person isn't really interested in what the text actually says, anyway. They aren't interested in the evidence. They're just looking for an excuse, a pretext, to get to their
preformed conclusion (i.e., that the Bible is false, so let me find a way to justify that--ah, here's one, Paul admits to lying). At that point, you've done your job. Put them in God's hands, answer any further questions they have, and move on.
So says I.