The New Testament does not use the word “legalism” and, therefore, it is thrown around today pretty carelessly.  The most common misunderstanding of the idea is that it only applies to salvific matters.  This is the common refrain from today’s fundamentalist.  “Our extra-biblical rules are not legalism because we aren’t saying you have to do them to be saved!”  While it is correct to view extra-biblical regulations as legalism as it applies to our justification.  Should it not also be shunned as it relates to our sanctification?  I’ll use the word “legalism” in at least two senses, but both have a common root problem.

1. Legalism means treating biblical standards of conduct as regulations to be kept by our own power in order to earn God’s favor. In other words legalism will be present wherever a person is trying to be ethical in his own strength, that is, without relying on the merciful help of God in Christ. Simply put, moral behavior that is not from faith is legalism.  The legalist is always a very moral person. In fact the majority of moral people are legalists because their so-called Judeo-Christian morality inherited from their forefathers does not grow out of a humble, contrite reliance on the merciful enabling of God. On the contrary, for the legalist, morality serves the same function that immorality does for the antinomian, the free-thinker, the progressive, namely, it serves as an expression of self-reliance and self-assertion. The reason some Pharisees tithed and fasted is the same reason some German university students take off their clothes and lie around naked in the park in downtown Munich. The moral legalist is always the elder brother of the immoral prodigal. They are blood brothers in God’s sight because both reject the sovereign mercy of God in Christ as a means to righteousness and use either morality or immorality as a means of expressing their independence and self-sufficiency and self-determination. And it is clear from the NT that both will result in a tragic loss of eternal life. So the first meaning of legalism is the terrible mistake of treating biblical standards of conduct as regulations to be kept by our own power in order to earn God’s favor. It is a danger we must guard against in our own hearts every day. And please know that my old self is just as prone to it as anyone.
2. This is the most common brand of legalism practiced today in modern fundamentalism.  The erecting of specific requirements of conduct beyond the teaching of Scripture and making adherence to them the means by which a person is qualified for full participation in the local family of God, the church. This is where unbiblical exclusivism arises. There is no getting around the fact that the church does not include everyone. We do exclude people from membership because we believe worship should imply commitment to the lordship of Christ, the head of the church. But exclusion of people from the church should never be taken lightly. It is a very serious matter. Schools and clubs and societies can set up any human regulations they wish in order to keep certain people out and preserve by rule a particular atmosphere. But the church is not man’s institution. It belongs to Christ. He is the head of the body, and he alone should set the entrance requirements. That is very important!