The pure definition of “Legalism” is the wrong use of laws or rules. It is taking a part of scripture out of the whole context and claiming that this is what God means. Only the Ruach HaKodesh can do that. And, it is not often what we think according to what we see at first blush. For example there is a form of legalism that uses rules and commandments as the way of salvation. Such laws in and of themselves may be good and proper, but not put according to what the Lord is saying to us can render them void of meaning and could actually be dangerous. Any truth out of balance will lead to heresy and people can make the Bible say anything they want if left to their own natural devices. For example: The law is good but it will not save a soul. Only the blood of the Messiah can do that. That is why Paul warns against the view that salvation can come about by keeping the law. And it was this wrong view of the place of the law in our lives for salvation that the Judaisers erroneously taught. The Torah is God's Word and a wonderful thing but unless the Lord builds our house we are laboring in vain. Yeshua is the living Torah!
Among believers in Yeshua HaMashiach there is also a kind of legalism that teaches that, although we are saved through faith in Messiah, our growth spiritually is also a matter of submitting to certain rules or standards. This too is an error of our legalism that many fall into very easily. Your growth in Messiah is dependent on developing a close knit union with Him through your relationship with Him via the Holy Spirit. It is also the Holy Spirit who teaches us all the things we need to know. The Torah actually means 'instructions' and we need the great teacher, the Holy Spirit to guide us in our decisions in life and our spiritual growth. Therefore, a person's Messianic growth is not properly judged by whether or not one keeps the prescribed rules: such as going to movies, no dancing, no gambling, etc. Make no mistake about it: these rules might have value in keeping believers from certain select sins, but they are not a substitute for the fruit of the Spirit. That is the Holy Spirit's domain and if you leave Him out at any juncture you have again misused the instructions of God's Word. Without HIM we can do NOTHING!
Another form of legalism elevates mere human preferences to the level of biblical absolutes. For example, there are some believers that have taught that no follower of Yeshua, Jew or Gentile, should have a beard or that no woman should wear lipstick, or you have to dress according to a certain set of standards. These cultural differences are held with the same convictions as important doctrines from scripture. This is dangerous. This type of legalism puts up a wall for the non-believer who wouldn't know the difference. In fact, one of the problems I see in Messianic Judaism itself is the elevation of the Talmud, the oral traditions, to the same place as scripture. These oral traditions are exactly what Yeshua warned against when He said, "Beware of the leaven of the Pharidsees and Saducees." Their oral thoughts, even thought to have been coming from the Torah itself added man made rules held up as the Word of God. This is confusion. This confusion has watered down the message of the good news of Yeshua the Messiah in many congregations and has hurt the movement and brought spiritual stagnation in many places. It does not work when we see various man-made standards imposed and elevated to be an essential doctrine of the Messiah. Only the Bible, the Word of God can show us the way, but we have to learn how to rightly handle it. The blood shed by our Lord always should be held out as as the pivotal element of our salvation and life in Him. Sometimes, even when what we believe looks righteous and is believed with good motives, we can end up being in serious legalistic error if we don't get the full counsel of the Holy Spirit and don't rightly divide His Word. Many of the Brit Chadashah/New Testament epistles (especially the book of Galatians) contain wonderful sections intended to correct legalism, which was warping the pure teaching of the Gospel even 2,000 years ago. I want to encourage all believers to study the Scriptures and discern whether or not their personal standards and communal teachings align with the Spirit and content of the Word of God (Acts 17:11).