In a recent, helpful and accessible article on the perspicuity (clarity) of Scripture, Wayne Grudem writes the following under the heading ‘Scripture affirms that it is able to be understood but not all at once’:
A useful analogy, then, might be to picture the clarity of Scripture as a journey to a distant mountain that we see clearly from afar but see in more detail—and understand more of what we see—as we journey toward the mountain over many months and years. We can see it from the beginning of our Christian lives, and we truly see and understand something about it, but a lifetime of seeking deeper understanding will be repaid with a lifetime of growth in knowledge and wisdom.
We might even imagine various signs on the mountain. Some, like “believe in the Lord Jesus Christ and you will be saved” (Acts 16:31), are written in huge font that can be seen from a great distance. Other signs become visible shortly after the journey has begun, and teach us to trust God and obey him daily. Yet other signs appear in small font, not visible at first, and when we come close enough to read them, they announce topics such as “predestination” and “millennium” and “the future of Israel” and “preaching to the spirits in prison” and “the relationship between God and evil.”
And even when we can read those topics on the signs, we find that a partial explanation is in yet smaller print, and a fuller explanation is in tiny print. And then at the end of that tiny print we find statements that say, “But who are you, O man, to answer back to God? Will what is molded say to its molder, ‘Why have you made me like this?’” (Rom 9:20). “The secret things belong to the Lord our God, but the things that are revealed belong to us and to our children forever, that we may do all the words of this law” (Deut 29:29). “Who is this that darkens counsel by words without knowledge? Dress for action like a man; I will question you, and you make it known to me. Where were you when I laid the foundation of the earth? Tell me, if you have understanding” (Job 38:2–4). And then we say with Job, “Behold, I am of small account; what shall I answer you? I lay my hand on my mouth. I have spoken once, and I will not answer; twice, but I will proceed no further” (Job 40:4–5).