1. I've seen Protestant apologists and theologians struggle with sola scriptura. Is that a damaging admission? No. For one thing, I see Catholic apologists and theologians struggle with their own position. Both sides have struggles.
2. Suppose someone raises an objection to your position, and you don't have a good answer. That could mean one of two things.
i) Your position is wrong
ii) The question is wrong
There are no good answers to bad questions. Sometimes the question is the problem. Take loaded questions that have dubious assumptions.
3. It's quite possible not to have the right answer, but sense that someone else has the wrong answer. Many Protestants look at Roman Catholicism and think, "Whatever the answer is, that's not it!"
This parallels the history of science. There's a process of elimination. Take a brilliant young scientific maverick. He thinks the standard paradigm is wrong. He doesn't know what the right answer is–yet. But he can recognize a wrong answer even though he doesn't have the right answer. And he has to rule out bad explanations as a preliminary step to make progress in finding the right explanation.
Likewise, even if a Protestant didn't have a good answer to objections, that doesn't mean he can't spot a wrong answer.
4. The stock objection to sola scriptura is that it fails to settle theological controversies. Scripture isn't self-interpreting. Without a living interpreter, Christians disagree about what it means. Scripture alone fails to secure doctrinal consensus.
However, we can flip that around. If Scripture alone fails to secure doctrinal consensus, then that's not the function of Scripture. That doesn't mean sola Scriptura is false. Rather, that means Catholics have misidentified the purpose of Scripture.
5. Catholics approach the question from an a priori standpoint. They have an expectation about God's intentions for "the Church". God will intervene to protect "the Church" from error.
Ironically, this parallels the argument from evil, which has the same a priori structure. If there's an omniscient, omnipotent, and benevolent God, he'd intervene to prevent evil, but since there's evil, God does not exist.
The argument operates from an expectation about what God would do or should do. Since that expectation is disappointed by experience, it follows that God doesn't exist.
But we can turn that around. If God doesn't intervene to prevent certain kinds of evil, then that doesn't falsify God's existence–rather, that falsifies an armchair expectation about what God would or should do.
Suppose you use a spoon to cut a steak. You complain about how ill-designed the spoon is. Surely there's a more efficient way to cut a steak. No doubt.
Does the spoon suffer from a design defect because it doesn't work as well as a steak knife? The spoon may be ideally designed to do what a spoon is supposed to do. The problem isn't with the tool, but misuse of the tool.
6. Even if you consider the Catholic alternative, does it solve the problem it posed for itself? It's not like Catholicism actually secures consensus. Take "ecumenical" councils like Trent, Vatican I, and Vatican II. The bishops don't think alike when they go into the council, and they don't think alike when they leave the council.
Competing factions are represented at "ecumenical" councils. As a result, compromise is sought to get enough votes for passage. When the vote is taken, there are winners and losers.
The losers aren't persuaded that they were wrong. In public they may submit to the results, but in private they remain unconvinced. In some cases, moreover, because the documents were deliberately ambiguous to forge a winning coalition, the losers can interpret the documents to agree with their own position.
7. Suppose we infer the purpose of Scripture from how it actually functions in the life of Christians. It guides them through life. They locate themselves in Scripture. They find their own story in the story of Scripture. They join the ongoing pilgrimage.
8. But how can it be a guide if Christians disagree? How can it be a map if Christians get lost?
Actually, I think every Christian is a little lost. Some Christians are more lost than others. But I don't mean "lost" in a damnatory sense.
There are degrees of lostness. Suppose you grow up in a mid-sized city. It's small enough that you know parts of the city very well, but it's large enough that you may lose your bearings if you go into a strange part of town.
Here's the thing: you can get lost in your hometown, but you can't get totally lost. Because you have a good general knowledge of the layout, if you make a wrong turn, you can continue to driving in that direction, or experiment with different routes, until you find a landmark. Then you exclaim, "So that's where I am!"
Or suppose you're a tourist visiting an island like Port Townsend. You don't know your way around. You may lose track of where you are.
But even if you're lost, you're still on the island. There are boundaries to how lost you can get. The island is surrounded by water. That's what makes it an island. The roads only go so far before they circle back or run out at the sea.
Even though you may lose your way, you can only get a little lost. You may be temporarily lost, but you can't be hopelessly lost. For the island limits how lost you can get. The island imposes a physical barrier on your degree of lostness. You may be lost somewhere on the island, but your disorientation is within the confines of the island. You won't turn up as a missing person. The authorities won't discover your body a month later.
Or suppose your home sits on 5-10 acres of land with meadows and woods, hills and dales. A fenced-in property. You have a 4-year-old son. He wanders off to explore the property. He becomes hopelessly confused. Is he lost? He is lost and not lost. He's lost in the sense that he can't find his way out. But he's not lost in the sense that he can't be found. If he doesn't come back, a parent or older sibling walks around the property until they find him. There are only so many places to look. It was safe to let him out of their sight because he can only go so far. How lost can he get? He was never truly lost.
To take a final illustration, suppose you get lost on a passenger ship. You make a wrong turn inside the ship. So many nooks and crannies and hallways leading to dead-ends.
But even if you couldn't find your way back, you are going wherever the ship is headed. The fact that you lost your way on the passenger ship doesn't affect your destination. You are lost, but the ship is not. The ship will ferry you to your destination even though you are lost onboard.
9. Sola scriptura doesn't mean we're saved by Scripture alone. In addition to Scripture, we're saved by God's grace and providence.
And that may be why God doesn't intervene to prevent Christian disagreement. We're not saved by our own cleverness. We're not saved by having 20/20 theological insight.
10. I'm not saying Bible readers can't be lost in a damnatory sense. But the good shepherd protects his sheep. To be lost in God's pasture, like the "lost" child in the fenced-in property of his parents, delimits how far you can stray.