Little children, keep yourselves from idols. -1 John 5:21
This verse almost seems out of place. John has spent a great deal of time establishing that as Christians we are to love one another. He has also spent a great deal of time talking about the signs of a true Christian and assurance of salvation. Then suddenly, almost as an after thought he ends with "keep yourselves from idols". Why this after thought?
John has just finished talking about what a Christian should "look like" in terms of spiritual virtues. But there are always those who will pervert that and legalistically make outward appearance, good deeds and ritual the gold standard for what a Christian is. Would this not be making an idol out of one's dress, and good deeds or religious ritual? Our Christianity is to come from the heart. Our standing before God is based on what Jesus Christ has done for us and a heart changed by Him, not on what we wear, good deeds we do or religious rituals performed. And so we need to keep ourselves from making idols out of these things.
I'm not saying these things are not important, but rather, they do not affect our standing before God in Christ Jesus, so we should not legalisticly elevate them and impose them on others as if they are the measure of salvation.