Read Galatians 1.
As our society becomes more secular, it is a relief when we find others who profess to know Jesus Christ. However, many people and groups have adopted the name of Jesus without embracing everything that the Bible teaches about Christ. Since they claim to love Christ and may say many things about Christ that we find agreeable, we want to affirm them as Christians and fellowship with them, too.
But, the scriptures warn us here (and elsewhere) to be on guard against “a different gospel” (v. 6). The church at Galatia was caught in a struggle over “a different gospel” when Paul wrote this letter to them. After receiving the good news that Christ alone saves people by grace alone through faith alone, they welcomed teachers who said that true faith in Christ must be accompanied by obedience to Old Testament law.
Paul said that was a “different gospel” and was “really no gospel at all” but rather an attempt to “pervert the gospel of Christ” (vv. 6b-7). It was “no gospel at all” because the good news has been replaced by the old news—obey God or else. Our faith in Christ teaches that the merits of Christ’s good works on earth (theologians call this his “active obedience”) and the penalty Christ paid for sin (Christ’s “passive obedience”) are applied to us by faith. You don’t need to obey the Law because Christ obeyed it perfectly and, by faith, God has credited you with that perfect obedience.
You don’t have to fear God’s penalty for your sins because Jesus paid the penalty fully through his death on the cross. Any “good news” that requires something more than what Christ has done for us is not good news at all; it is very bad news because we can’t save ourselves or contribute to our salvation in any way. We are fallen so we will inevitably fail to do whatever good works that other gospel would require of us. And, God isn’t impressed by our good works anyway, so we wouldn’t earn anything from him even if we could be perfect.
Note that Paul warned them and us to beware of the messenger in verse 7. Even if Paul himself were the messenger or if an angelic being appeared with supplementary instructions, that messenger would deserve, not God’s blessing but God’s eternal curse (v. 8). Just in case we missed it, Paul repeated this truth in verse 9.
It is so comforting to find someone else at work who believes in Jesus, isn’t it? Our tendency when we feel isolated in a secular world is to hold on to anyone else who claims to follow Jesus, too. If they truly do follow Jesus, that is an extraordinary gift.
But, if that person tells you that you need Christ plus something else, beware! The message they have believed is not good news that sets you free from the power of sin; it is, instead, a perversion of our faith (v. 7b) which will enslave you.