C.J. Mahaney has written a helpful article, encouraging us to fight legalism and cling to the gospel. He writes:

Pause for a moment and remember.

Remember where you were, and what it was like ... that moment when you understood the cross for the first time ... when you really grasped what happened at Calvary, and what it truly means that Christ died for your sins, what it truly means to be saved.

Remember the passion for Jesus you had? Remember the joy and overwhelming gratitude to God that came from knowing your sins were forgiven?

Now think about your Christian life today. Have you moved on to other things? Maybe you're primarily focused on fighting lust, or pursuing godly relationships with the opposite sex, or battling pride, or cultivating patience.

If so, life is probably quite different for you now. Perhaps you often lack joy, or wonder why you can't make greater progress in spiritual maturity, or feel condemned when you sin. So you study your Bible more, or attend another small-group meeting, or serve in new ways at church, or read the latest book.

All these practices are good. Some are vital. But let me suggest the likely root cause of your problems: Perhaps you have simply drifted from the message that saved you. If you lack passion for God, if you sometimes wonder where the joy went, then consider: Are you still clinging to the gospel? Whether you grew up in church or were saved on the streets, you were saved by the same simple message: Christ died for your sins.

The way we began this walk of faith should be the way we continue. We began with the gospel. We should continue with the same simple faith in the same profound gospel. Our tendency to drift away from the message we began with isn't new. Paul the Apostle addressed this tendency when he wrote:

"O foolish Galatians! Who has bewitched you? It was before your eyes that Jesus Christ was publicly portrayed as crucified. Let me ask you only this: Did you receive the Spirit by works of the law or by hearing with faith? Are you so foolish? Having begun by the Spirit, are you now being perfected by the flesh?" (Gal 3:1-3, ESV)

Paul reminds the church of the message the church began with: "Jesus Christ ... crucified." The cross is where we should be planted. The cross reminds us that our best efforts could never achieve forgiveness from God. And the cross reminds us that Christ's work on our behalf is forever finished, so our best efforts can never add to His work.

How quickly we drift from this essential message! We begin basing our relationship with God on our performance. We want to substitute our works — our Bible reading, our church attendance, our church participation — for Christ's finished work. We easily fall into the subtle but serious trap of legalism, because every one of us has a legalist lurking within.

If you're unfamiliar with this term, here is how I like to define legalism: Legalism is seeking to achieve forgiveness from God, justification before God, and acceptance by God, through our obedience to God.

In other words, a legalist is anyone who behaves as if he or she can earn God's approval and forgiveness through performance. At its heart legalism is self-atonement for the purpose of self-glorification and ultimately self-worship. Many of us (and I include myself here) can approach legalism casually. But legalism is serious and it is deadly.

I can assure you that in the next 24 hours you and I will face the temptation of legalism — we will once again be challenged and confronted by the legalist within. In order to combat this sinful tendency in our own hearts, it's critical for us to stay planted in the good of the gospel — to continue in the message we began with.

Here are three ways you can seek to remain planted in the good of the gospel on a daily basis.

First, remember the cross. "It was before your eyes that Jesus Christ was publicly portrayed as crucified." Paul reminded the Galatians of the cross, and he reminds us as well, because our daily tendency and temptation is to forget the cross. Recognize this tendency in yourself and remind yourself often of the cross. Read cross-centered books, listen to cross-centered preaching, and memorize Scripture verses pertaining to Christ's work on the cross.

Second, recall your conversion. "Let me ask you only this: Did you receive the Spirit by works of the law or by hearing with faith?" With this question, Paul points us all back to the message that saved us. He wants us to begin interrogating the legalist within, whenever legalism rises up to try to dilute or deny the unique saving power of God's grace. To recall how we were converted is to be reminded of grace. As a practice, I seize every opportunity to share my testimony with other Christians, and I ask them to share theirs. I find this practice helps us marvel at grace together.

Third, review your hope. "Having begun by the Spirit, are you now being perfected by the flesh?" Here is another telling question for your inner legalist and mine. So please be very clear about this: You will never be more justified — more accepted by God and righteous in his sight — than you are right now or than you were that first moment you exercised the gift of faith in the person and work of Jesus Christ. Our hope for each day is not in trying to earn God's forgiveness, but to look outward and upward, trusting in the work of God's Son on our behalf, for our justification is in Him, permanently and forever.

I recommend these practices because I'm very aware of my temptation and tendency to attempt to smuggle some of my own character into God's work of grace. I try to add what I do to what Christ has already done. I face the constant temptation to legalism. But planting myself near the cross helps me, by God's grace, to turn away from legalism.

There is hope for us in the gospel. The gospel helps us break free from legalism. The gospel takes my eyes off myself and puts them on God. So in your fight against the legalist within, remember the cross. Recall your conversion. Review your hope.

Only in the sure and certain hope of the gospel can we find again that fullness of God-centered joy, passion, and gratitude. You began with the gospel, so stick with the gospel.