As our church enters the New Year, we have a single resolution: to understand the gospel better by allowing it to seep down and influence every area of our lives. Through every relationship, every pursuit, every conversation, every task, and every free moment, we want to become more aware of the three things that make up the gospel:

1. The greatness of God’s glory
2. The greatness of our sin
3. The greatness of God’s grace that bridges the two

We’ve reworked a very helpful diagram from The Gospel-Centered Life by Bob Thune to show how this works over the course of our lives:

This shows the life of someone who’s walking closely with God over time. When you’re saved by God, you don’t see much of God’s holiness, and you don’t see much of your sin. But over time, God gives you more experiences like he gave Isaiah in Isaiah 6:1-7. You see more of his glory and his holiness. You see more about him that’s awe-inspiring and jaw-dropping.

In the light of his glory you see more of your own sinfulness, like turning on the lights in a room and seeing the cockroaches scatter. You see beyond the obvious external sins, and you start seeing the heart-level ugliness inside. And the more you see how far apart you are from God, the bigger the cross becomes. You see how incredible God’s grace is, poured out on the cross to bridge the gap between his holiness and your sinfulness. And that’s how the gospel grows and bears fruit in your life like Paul talks about in Colossians 1:6. You start accepting more of God’s grace, and the result is that you start looking more like God.

But there’s a problem. We’re sinful, so most of us don’t always live that way.

We don’t always grow in our awareness of God’s glory. We’re happy to have him as our copilot, just there to back us up when we need him. And we don’t always grow in our awareness of our sin. We keep on doing the same things we’ve always done, without ever stopping to ask ourselves whether we’re pleasing God or not.

And so the cross just stays small. We don’t appreciate the grace of God very much, so it doesn’t affect us very much. We stay the same.

The theologian Tertullian, who lived 150 years after Christ, said, “Just as Christ was crucified between two thieves, so this doctrine of justification is ever crucified between two opposite errors.” According to Tim Keller (PDF), he meant that there are two errors we fall into that pull us away from the gospel. Either you can diminish God’s glory, or you can inflate your own holiness.

There are words for those two thieves: Legalism and Relativism.

Legalists inflate their own holiness. They see God as holy and just, and so they try to come up with ways to make themselves just as holy. They like to have a lot of rules to live by, and if they can successfully follow the rules, then they feel pretty good about themselves. If you read your Bible 30 minutes a day, then you’re holy. If you go to church every week, even when you’re on vacation, then you’re holy. If you can go a whole month without looking at any dirty websites, then you’re holy. They don’t need God’s grace, because they’ve got all their rules instead!

Relativists diminish God’s holiness. They like see God as the nice, loving old guy in the sky, who doesn’t set too many expectations. They might see sin, but it’s mostly in society at large. If they see it in themselves, it’s a result of their exposure to the society. They emphasize freedom and love and grace, but since they don’t have a proper view of God’s holiness, they don’t really have a proper view of grace. Their idea of grace is just niceness. It’s still pretty small.

We have thieves on each side of the gospel, and both of them keep the cross small. Both of them keep the gospel from bearing fruit in our lives. And we allow both of them to do it all the time:

• When you go to church, the thief of legalism will try to make you deadly serious in your worship, to make sure you worship our holy God in complete holiness and earn his favor. The thief of relativism will try to make you casual and flippant in your worship, since God isn’t too far above you anyway. But if you’re living in the gospel, you’ll be blown away by God’s holiness and your sin, and you’ll worship out of sheer joy for the grace he’s lavished on you.
• When you’re going through a really tough time in life, the thief of legalism will try to tell you that you don’t deserve it because you’ve been faithful to God. You’ll end up bitter because God isn’t being fair. The thief of relativism will try to tell you that it’s OK to do whatever it takes to get out of the tough time… lie, cheat, steal, whatever. God won’t mind. But if you’re living in the gospel, you’ll see God’s glory and your sin, and you’ll see how God is using the tough time to make you more like him.
• When you meet a homeless guy on the street, the thief of legalism will try to tell you that he’s getting what he deserves, since he obviously hasn’t been as faithful to God as you have. The thief of relativism will try to tell you that he’s a victim of society, and he just needs a handout, not more religion pushed on him. But the gospel will tell you that you’re just as spiritually poor as he is physically poor, and you’re both in need of God’s grace, so you won’t have any problem giving him what he needs, physically and spiritually.

The gospel changes everything! Absolutely everything. So as we start this New Year, I’m praying that God will help us see the greatness of his glory, the greatness of our sin, and the greatness of his grace in absolutely everything.