Someone's said that if you aren't a liberal when you're 20 you haven't got a heart, and if you aren't a conservative when you're 40 you haven't got a brain. Whoever made that little quip, they were obviously over 40. They looked back at all those dreams and ideals, those beliefs that the world could be changed and made a better place, and thought, "No: just keep your head down and your nose clean, that's all you can do. Idealists and dreamers on one side, hard-nosed operators and downright crooks on the other – they all end up in the same place anyway, and nothing really changes."

The Bible book of Ecclesiastes expresses the same philosophy of life. In Chapter 8, the Preacher encourages people to keep their heads down and not make trouble: "Do not stand up for a bad cause, for the king will do whatever he pleases" (verse 3).

He doesn't believe in happy endings. "There is something else meaningless that occurs on earth: righteous men who get what the wicked deserve, and wicked men who get what the righteous deserve" (verse 14).

There's no justice; it's meaningless. And Ecclesiastes makes us ask, is the Bible right?

That's a different question from asking whether it's true. But is the Preacher right when he argues that if you shouldn't actually be wicked, you shouldn't be too righteous either; that nothing really makes any sense; that you don't challenge bad things because it won't make any difference; that you'll never understand everything so it's a waste of time trying; that you should just get on with your life and be grateful, without too many hopes and dreams?

What we have in Ecclesiastes is just one side of the conversation. We have Ecclesiastes in the Bible for a reason; it's a rich and thoughtful book. But if we only read Ecclesiastes, we'd end up with a faith that was impoverished. The Bible is God's word to us, but sometimes we learn most from it by arguing with it.

First, don't just cave in when authority goes bad.

The first few verses of the chapter are about submitting to authority, even when the authority's wrong. It's also about accepting that you aren't going to win, so there's no point in making yourself unpopular or exposing yourself to risk.

But the Bible is full of people who did that. In our own time and place, we know what happens when people don't stand up for what's right. There are brave people who expose scandals in the Church or in politics, and sometimes they suffer for it, but they're doing the right thing.

There are many, many things in this world about which we might need to take a stand. The tempation is always to think it's someone else's problem, not our own, and that we should just keep our heads down.

Ecclesiastes is true, because the Bible is true; but the Preacher is wrong. God gives us responsibility. We can't be silent when there's a word to be spoken.

Second, don't think right and wrong don't matter.

The tendency of the Preacher is to go for a grey, pragmatic middle ground. Pragmatism is about being sensible, settling for what works and is reasonable. Sometimes that's not wrong. But sometimes God needs us to be extreme in our love of the right thing.

Dirk Willems was a Protestant, an Anabaptist, in 16th-century Holland when it was ruled by Catholic Spain. It was at the height of the terrible wars of religion. Dirk Willems was caught and imprisoned, but he escaped and fled over the frozen canals with the guards following him. He crossed a canal, but as the man behind him crossed, the ice broke and he fell in. , drowning. Dirk turned round and pulled him out; the other soldiers came up and recaptured him. Instead of letting him go and pardoning him, they burned him at the stake, as he knew they would.

The Preacher in Ecclesiastes would say, what a fool: "There's no justice. It's meaningless. So I commend the enjoyment of life, because nothing is better for a man under the sun than to eat and drink and be glad" (verse 15). The believer says, what a witness. People like Dirk Willems bear witness to a different scale of values altogether.

Third, don't stop thinking.

The Preacher says: "No one can comprehend what goes on under the sun. Despite all his efforts to search it out, man cannot discover its meaning. Even if a wise man claims he knows, he cannot really comprehend it" (verse 17).

What we have here is a mixture of real wisdom, and boredom and disillusionment. Today, we know far more about how the world works, at every level, than we ever have. There's been an explosion of knowledge. And we will never get to the end of exploring the human mind and heart, in all its glory and all its shame. So we should never stop asking questions and never assume that some subjects are off limits.

Paul wrote to Colossians that "all wisdom and knowledge are hidden in Christ" (2:3); there is nothing to be afraid of in any questions that we might have.

Ecclesiastes is a Wisdom book. But real, eternal wisdom is found in Christ; we look to him to guide us.

Follow Mark Woods on Twitter: @RevMarkWoods