Rodger has reminded me that everyone develops some sort of systematic theology. We can't help it: God has made us culture-creating people, and theology is part of that. That's probably an important fact to keep in mind. Whether you read it in a book or develop it as you read through the Scriptures, you will end up with some kind of systematic theology. And to be honest, the theology you read in a book is likely much better thought out than the one you develop yourself.
On the other hand, if God had wanted to give us a systematic theology, He could have. But He did not. He gave us the scriptures: a collection of texts from several different writers, in different languages, written at different times and in different styles and of different genres. What God gave us does contain some doctrinal text, but that is a very small minority of the total words He gave us. The scriptures are a collection of poetry, history, narrative (which includes history, but certainly isn't all history), prophecy (some of which is pretty plain, some is very obscure), personal letters, and even a love song. We must not approach God's word with the idea that it's primarily a legal text, or a doctrinal text, or even a history text. It contains all of those things, but it's not merely any of them.
This, to me, is a real issue with our developing theologies: so many Christians talk like the scripture is a collection of raw ingredients whose purpose is to be turned into a final product. As though their theologies are somehow an improved form of the words God has spoken. Let's say right now that the word of God is of infinitely more value that any understanding of it you or I might have (Proverbs 30:5–6).
We seem incapable of not allowing our theologies to displace Scripture in our own minds. I've mentioned before that "helpful tool" becomes "interpretative framework" and then "replacement for Scripture" very quickly. There is, I'm sure, an application of "leaning on our own understanding" (Proverbs 3:5–6) in that.
Scripture speaks very highly of the fear of the Lord. It is the beginning of knowledge (Proverbs 1:7), the beginning of wisdom (Proverbs 9:10), and even the summation of wisdom (Job 28:28). The Lord speaks highly of the man "who trembles at my word" (Isaiah 66:1–5). The Lord Jesus accused the Pharisees of nullifying the word of God by "the traditions of men" (Matthew 15:3–9; Mark 7:1–13). I have seen that play out many times.
I was talking to a man a few years ago who was telling me about a church where the pastor was an excellent Bible teacher, but they fall into error because "they didn't have the Creeds." Whatever he meant to say, what he actually said was the the Creeds are capable of protecting us from error where God's own words are not. Whether or not saying something like that is actual sin, it certainly is not the fear of the Lord.
Many years ago, someone told me that he was quite comfortable disallowing speaking in tongues in the church despite 1 Corinthians 14:39. He said the context of 1 Corinthians 14 is clearly at the start of the present dispensation, and we are past the point of the Lord working through those things. That may or may not be true, but it's indisputable that 1 Corinthians 14:39 commands not to forbid speaking in tongues. I cannot see his position as anything other than deliberate disobedience to the word of God.
I've noticed a tendency to refer to the parable of the Sower as the "parable of the soils." I mentioned this before. While we don't want to make someone a transgressor for a word, the fact is that the Lord Jesus told many parables, and the parable of the sower is the only one He named. So if we want to refer to the parable of the Prodigal Son as "the parable of the Forgiving Father," we're really just replacing one man-made name with another. But "the parable of the Sower" is the title Christ Himself gave to that particular story. To give it another name – even for what seems like a good reason – implies the Lord got the name wrong when He named it. Again, this might not be actual sin, but it's not the fear of the Lord.
Those three examples are from my own experience, and they're from people with widely varying theologies. So it's not like there's a problem with "their" theology but not "ours." Every theology becomes an excuse for us to ignore the words God has spoken and replace them with our own. It seems to me there's no path to Pharisaism as direct as being "well taught" in theology.
And in case I'm not being clear, the issue isn't the theology per se, but our own hearts. We have such a desperate need to move ourselves into the center that we'll replace God's words with our own at the slightest excuse. The problem isn't "Calvinism" or "Arminianism" or "Dispensationalism" or any other "-ism." The problem is that we don't want to bow to God's word. Any theology we can erect between ourselves and His words can be used as a way to hide from God.
It's probably not the worst idea to read through the Gospels, putting ourselves in the Pharisees' place. It might be the most accurate way to read them, and it might open our eyes a bit.
Now, because I have a friend who objects to Biblicism on the grounds that it's easy for it to become proof-texting, I'll just add this... To the extent that I advocate Biblicism (that is, taking the word of God as not merely infallible but also sufficient), I am doing so with the assumption that we bow to the whole word of God. Using Biblicism as an excuse to be lazy about theology is sin too. Scripture doesn't excuse slothfulness, especially not when it comes to the Scriptures. If the first eight chapters of Proverbs convince us of nothing else, it ought to make us certain that the Scriptures demand work.
Part of the temptation to replace Scripture with theology is that it's a lot less work.
I absolutely encourage reading other books in addition to the Bible. I cannot overstate how much reading Darby and Newell and Nee and Kelly (and others too!) has helped me. The effort to find, acquire, and read those books was effort well spent. But I must not allow myself to put them into the place of God. The book God gave is perfect, the books Darby wrote are not.
And even if they were – even if you were somehow able to find the perfect theology textbook – it would only address one part of what God has given. This is the point I started with: God could have given us a systematic theology text, but He did not. He knows what we are, and He gave us what we need. What we need is a collection of books written over several centuries by several different people: some of it poetry, some of it prose. When we try boil that book down, we always produce something less.
