Christians used to not drink alcohol based on convictions; now, all teetotalers are quickly dubbed legalists.
Christians used to avoid movies and dances based on convictions related to content and decorum; now, such people would be immediately dubbed fundamentalists.
Not so, among the 17th century Puritans. These men and women embraced convictions not to be saved (which is what a legalist really does), but they did it out of faith in a God who cares about every facet of our life.
Richard Rogers once said, "I serve a precise God." A precise God requires precision of life and conduct among his people.
J.I. Packer explains this well in his book A Quest for Godliness: The Puritan Vision of the Christian Life: "A precise God--a God, that is, who has made a precise disclosure of his mind and will in Scripture, and who expects from his servants a corresponding precision of belief and behavior..."
If you are ever labeled a legalist, embrace these steps:
1) First say, "Thank you for that observation. If this is true, I am in a grave situation. I will go now and prayerfully make sure my lifestyle choices are born out of gratitude for my salvation and not as the means to be saved."
2) Next, if after meditating on this and are confident it is a choice based on love and obedience toward God to express thanks for your salvation, return to your accuser. Tell them, "I believe my conduct in this particular area is just one simple gesture of gratitude and holiness to a God who has saved me from great sin and has invited into a life of precise holiness."