We ourselves are Jews by birth and not Gentile sinners; yet we know that a person is not justified by works of the law but through faith in Jesus Christ, so we also have believed in Christ Jesus, in order to be justified by faith in Christ and not by works of the law, because by works of the law no one will be justified. But if, in our endeavor to be justified in Christ, we too were found to be sinners, is Christ then a servant of sin? Certainly not! For if I rebuild what I tore down, I prove myself to be a transgressor. For through the law I died to the law, so that I might live to God. I have been crucified with Christ. It is no longer I who live, but Christ who lives in me. And the life I now live in the flesh I live by faith in the Son of God, who loved me and gave himself for me.
— Galatians 2:15–20 ESV

Hello, my name is David, and I am a recovering legalist. I’m not exactly sure how I became a legalist, but somewhere along the way, I began to see faith through the lens of “what can I do for God”. Give me the rules, the facts and the guidelines, and I will use my personal will and effort to achieve a passing grade — and eventually, I will probably earn an A. There is undoubtedly a lot of pride in that position. The idea that my actions hold the solution to sin is really an offense to the cross. The gospel clearly communicates that it’s not about what I do but rather about what Jesus has already done. My salvation is not dependent on me, it is dependent on Him.

However, I still feel the pull to build a system of rules that I can use to justify myself as worthy of approaching God. Of course, the system I build or choose tends to be one where I perform better than most. It’s easy to feel good about myself when I measure myself against someone else who is worse. The problem is that I am not measured against anyone other than a perfectly holy God.

So the fallacy is easy to see. I am not to be a slave to the law for the law merely identifies the problem with no ability to address it. God, on the other hand doesn’t merely expose the issue, he solves it (that probably should be in the past tense because the work has already been done).

In this way, the law most closely resembles an MRI. An MRI is effective at identifying a health problem but does nothing to solve it. As a matter of fact, you could get an MRI every day for a year, and you would merely watch the issue grow more and more deadly. God, on the other hand, is the Great Physician who, through the blood of Jesus, administers the grace that was earned at the cross.

I have been crucified with Christ. Therefore, I no longer claim any ability to fix my situation by works of the law. I am fully resting on his ability to live out the resurrection life in me. That’s not legalism. That’s the power of the gospel.