The dictionary defines legalism as strict, literal adherence to law. In Christian circles, this strict, literal adherence to law (obedience) gets labeled legalism and is looked upon as being negative. In other words, you don't want to be considered a "legalist" when referring to your relationship with God.
I don't know of anyone who would argue that we should not adhere to the law of the land in a strict, literal way. Those who don't, usually end up in trouble with the "Law".
If you are caught speeding it would not be wise to get into an argument with the officer as to whether he is being legalistic or not. It is his job to be legalistic and he is being paid to be legalistic. If he decides that he is no longer going to be legalistic about the law he will lose his job.
So there is nothing inherently wrong or negative about being a legalist. In fact God is a legalist. He has laws, which He himself keeps strictly and literally, and He expects everyone to keep them strictly and literally as well. Isn't that where Satan ran into trouble, followed by Adam and Eve? There are many examples in the Bible of those who suffered because they didn't believe God meant for His Word and laws to be kept strictly and literally.
So, why do most Christians look at being "legalistic" as a negative thing, and those who endeavor to keep God's laws strictly and literally as being "legalistic", and in doing so are doing something undesirable, negative?
The majority of Christians have lost sight of or have not been informed of the fact that God's law cannot be kept in one's own strength. So, when they try to keep it in their own strength they very quickly find that it can't be done and they become discouraged and frustrated.
When they discover that it can't be done they take it for granted that there is no other way that it can be done but in their own strength. So, when they see someone keeping God's law they take it for granted that they are doing it in their own strength, as most are trying to do. But at the same time, seeing others keeping God's law makes them feel inferior, weak, guilty, angry, etc. since they have not been successful. Yet, at the same time, they are convicted that they should be keeping God's law. In order for them to feel better about themselves they look down on those who are keeping God's law and, for lack of a better description, call them "legalists" in a derogatory way.
So, since this is the way that the word legalists is being used by most Christians, let's look at our relationship to God and His law from their viewpoint.
When one keeps God's law with the wrong motives - fear, God's approval, or to earn salvation - this is a legitimate concern. A "legalist" not only does the right thing for the wrong reason, he also does the right thing in his own strength.
So, who then isn't a "legalist"? There are two groups of individuals who are not "legalists".
First, there are those who do absolutely nothing that God asks them to do. In other words they do nothing that we would consider "good". These people are described in Genesis 6 and they are not legalists.
Then there are those who have learned how to keep God's law and strictly and literally do what God asks them to do. They would rather die than displease God. The difference is that they do it through the power of the Holy Spirit in them, not their own strength. Why? Most Christians have become very aware that God expects obedience of them and have also become agonizingly aware that it is an impossibility for them to keep God's law in their own strength.
Because of this they have invited the Holy Spirit to empower and control them. Paul describes these people in Romans 6 and 8, as well as elsewhere. John describes them in 1 John 3. They are living under grace, not under the law. They have happily discovered that grace is not only forgiveness for sin but power to keep them from sinning to begin with. They keep God's law by the power of God working in and through them, not their own strength. These individuals have found that they can do all things through Christ who gives them the strength to do so. They know that all God's biddings are enablings.
The true Christian does keep God's law (all of it) in the manner defined above, but it is how he keeps it that makes all the difference and in so doing puts legalism in a positive frame where it should be.
It is only the good works originating from a heart that is totally surrendered and submitted to God, a heart that delights to do God's will and whose greatest desire is to please God, that is not categorized as "legalism" in the negative sense.
Paul, in Romans 7, describes the condition of those who are endeavoring to keep the law in their own strength and he concludes that it is impossible and only leads to eternal death.
This is very serious. To review, "legalists" (in the negative sense) are keeping God's law and doing His will in their own strength, apart from being empowered by God. Anything good that they do which falls short of this is "legalism" by their definition! Matthew 7:23 defines those who were not empowered by God and who He did not recognize, saying He didn't know them. Those who are endeavoring to keep the law in their own strength are living under the law and are condemned by it, because they are not keeping it under grace, and Jesus says that He does not know them.
Most Christians are aware that keeping God's law will not save them. This is true, but we cannot be saved while breaking it, either. The only way one can acceptably obey God's law is through surrendering and receiving supernatural power from the Holy Spirit, or as John says, by having His seed within us. 1 John 3:9
We call the individual who is Spirit-filled and Spirit-controlled, born again. These individuals are keeping all of God's law and are not "legalists". Why? They depend on God's indwelling power, not their own will power. They are keeping it from a true love relationship with Christ which empowers them, not a self-generated human love that is powerless. It's a supernatural love that is given to them by God.
The only ones escaping the label "legalist" are the truly born again Christian and the profligate - those who completely abandon Christian ways and do nothing right - sowing to the wind.
I don't want to be classed a "legalist". So, my options are clear. I must completely abandon my self-sufficient ways, repent of my desire to live my life in my own way, and admit to my great need of God's indwelling transforming power. God then accepts my actions and I can stay away from "legalism" in this surrendered state. I'm controlled by His Spirit.
Jesus did not come in order to do away with the law. He came to give us His power or grace, to empower us to keep the law since without His grace we are unable to keep it in an acceptable manor.
As usual, the devil has taken a perfectly good legitimate description of a fully surrendered committed Christian and given it a negative connotation. He does this so as to keep people from having a real relationship with God that gives victory over sin and allows them to keep God's commandments perfectly, through the strength an indwelling Savior.
We want to be a legalist in the correct sense of the word, not someone who only keeps part of want God asks them to keep because it is either too crucifying to self, too inconvenient, or because they just don't want to be considered a "legalist". These must be unaware that it will only be the legalists (those who are strictly and literally keeping all of God's commandments through His power) that Jesus will be coming back for.
The vast majority of religious people pride themselves that they are not "legalists", when, in fact, if they are keeping any of God's laws selectively and in their own strength, they are! In Revelation 3:14-22 John calls them Laodiceans. Why? Because they think that they are rich, and increased with goods, and have need of nothing; and don't know that they are wretched, and miserable, and poor, and blind, and naked. God says he will spew these out of His mouth.
We should really be calling those who are endeavoring to keep God's law in their own strength Laodiceans, not legalists. But doing this would expose those who are truly in trouble and alert them to their lost condition. The devil is not interested in attacking/enlightening these lukewarm professors. He is very happy with where they are. It is the true followers of God who are keeping God's law in the correct way that he is wanting to attack, so he takes a word, twists it, and uses it in such a way that it makes them look bad and the Laodicean look fine. But isn't this exactly what he wants? Satan loves it when he can get us to call white black and black white. He is tickled pink when even the true Christian doesn't realize what he is doing and falls into his word games as well.
In conclusion a legalist, as defined by mainstream Christianity, is an individual who is endeavoring to keep God's law in his own strength. God does not accept this kind of law keeping and it is right to look down upon this kind of law keeping. The fact is, this kind of individual can never be a legalist since they can't keep God's law strictly and literally in their own strength. Whereas the born again individual is keeping the law correctly. He keeps it strictly and literally through the power of the Holy Spirit working in and through him, not in his own strength. This is the only way that God accepts law keeping. A strict, literal adherence to law in this way is true legalism and is positive and the only acceptable way of keeping the law.
Instead of looking down on all law keeping as the majority of Christians do, calling it "legalism", we need to inform individuals as to how to keep the law in an acceptable way, guiding them away from Laodiceanism, which is the correct definition of law keeping in one's own strength.
2 Timothy 2:15