Our faith is to be supplied with knowledge (2 Peter 1:5,6). That is, our faith is pinned at the corners with truthful insights whose implications are being worked out in our lives. A failure to do so leaves us dangerously close to the "fool" of Proverbs - ones who have truth available to them, but who choose to ignore it.
Paul helps us with this subject of an informed faith when he writes 1 Corinthians - to believers who should know better. Several times through the letter he says, "Don't you know?" And they did, but they didn't. They know the words on the page, but the integration into decisions and behaviors had not penetrated. The following three "don't you know's" are illustrations of paper-truths that need to be made heart-truths.
"Don't you know that you (plural) are the temple of the living God?" (1 Cor 3:16). There are probably many applications, but here are two. First, the church, and the local church, is not first of all a human operation, but a divine operation. It is God's plan, God's initiative, God's transformation, God's instruction. As you look through the context of 1 Corinthians 3, notice how many times it says "God's," "God's," "God's." It is not ours. So the search for the perfect pastor/elder/deacon/drummer is not the highest priority. There ought to be a search committee looking for the leading of God's Spirit. And I'm sure that in many churches, there are people banding together to do just that. The church is not primarily about winsome personalities and compelling programs. It is people moved by the Spirit of God for the sake of Christ doing the things that Christians do - praying, serving, sharing Christ.
A second application is that we must stop trashing the church, even (or especially) the local church. Yes, it is indeed a group of bumbling people who would have a hard time finding their way across a bridge. But these idiots (lovingly so called) are God's idiots. And they probably know that they don't "get it" in large degree. I've marked Agur's statement in my Bible: "Surely I am more stupid than any man," (Proverbs 30:2). But still God loves us. He loves His church. We should talk about the church like God does, not failing to tell the truth, but to do so with love and affection.
"Don't you know that your bodies are temples of the Holy Spirit?" (1 Corinthians 6:19). While food may not be a big deal, how you treat your body is a big deal, and sexual relationships are a big deal. Let me be quick. If you are single, you should not act as though you were married. No sexual activity. If you are married, you should not act as though you weren't. Be a couple. I should have been this brief when I preached this.
"Don't you know that those who run in a race all run, but only one receives the prize?" (1 Corinthians 9:24). I don't think Paul's point is that he wants to beat out all other Christians. I think he is making the point that he is "all in" in this race, and that we should be as well. There is no such thing as "casual Christianity." To be a believer in Christ means to be a follower of Christ. It means to walk with/by the Spirit. It means to be adopted into a new family, engaged in a new covenant, and being part of a rigorous, sanctifying process that fits us for a new creation. Paul is a competitive Christian. He wants to win. He wants the team to win. He doesn't like it when a team member is distracted and misses an opportunity and let's the team down. Let's get involved.
Scripture is full of truth - many truths, that need to penetrate deep in our lives so that our actions and reactions are transformed. Peter wants your faith to be shaped by a penetrating, transforming knowledge. It will take the rest of your life. There is no time to waste.