A while ago, I addressed a few instances of Yeshua saying, "but I say" in what appears, at first glance, to be him nullifying the Law of God. One of those instances concerns swearing. But what's the relationship between swearing and cursing? And since the use of profane language is often referred to as "swearing" or "cursing", what's the relationship between profanity and the other two?
First, let's address the issue of swearing. Swearing is making a promise to do something, or to abstain from doing something. Leviticus 19:12 makes it very clear that we are allowed to swear, but that we are not to swear falsely. And if that were not clear enough, Numbers 30:2 makes it all the more clear that one must do as they swear to do. And Leviticus 5:4 warns us to be careful when we swear, lest we sin by failing to keep an oath we swore recklessly. Notice that Yahweh only gave provision for swearing by him. And also note how the Pharisees abused the "you shall not swear by My name falsely" of Leviticus 19:12 to say that if you swear by something other than God's name, you may do so falsely. Yeshua didn't take too kindly to that rule. By the way, James 5:12 is the same situation as Matthew 5:34. The "not" is a qualified not. The context proves that the proper qualifier is "falsely". Both passages say "do not swear falsely". Nowhere are we forbidden from swearing an oath.
Cursing on the other hand, is to declare harm or misfortune on someone or some thing. It's not a promise to do something, it's calling on God (or a false god) to bring judgement on someone or some thing. Just like with swearing, the "New Testament's" teaching on cursing is also misunderstood. Of course, it doesn't help that cursing and swearing are often conflated. For example, Romans 12:14 says "bless and do not curse" in the context of blessing those who persecute us. And in James 3:9-10, James rebukes those who curse others. The context of this rebuke concerns doing evil with the tongue. But we also have instances such as Acts 8:20-23, where Peter curses a man who just recently came into the Body of Messiah. Again, Peter cursed someone who just became a follower of Yeshua. The reason for this curse? This man thought that the Holy Spirit could be purchased with money.
So cursing isn't forbidden in all circumstances. There are times where cursing is absolutely called for. And like with swearing, it's not something to be taken lightly. And as shown in several instances, people can die from being cursed. And also, as shown in passages like Deuteronomy 23:5, Yahweh has the ultimate authority over curses and what happens as a result of said curse.
So that leaves profane language. Or to put it in layman's terms: "bad words" or "curse words". The concept that a word, by itself, is bad, is not from the Bible at all. It's from paganism. Words, in and of themselves, are not good or bad. It's the context in which they are used that is good or bad. Christians are generally taught to be offended by certain words because such words are "bad words". But this teaching does not come from Scripture. Now, obviously words have meaning, and it is important to take into consideration the meaning of a word when it is used. Using the wrong words in a sentence can convey a meaning that is not the intended meaning. But even this does not make a word by itself good or bad, since words by themselves are not good or bad. It just makes certain words not fit to convey a particular meaning. Yeshua warned that we will be held accountable for every careless word that is spoken.
If words by themselves are not good or bad, then what about passages like Colossians 3:8, or Ephesians 5:4? Those passages are not condemning words that culture says are "bad". Rather, they are condemning something known in Hebrew as "the evil tongue". And if you look at the context of both passages, you'll see that both concern abstaining from evil, including evil speech. Remember Deuteronomy 12:32. Examples of evil speech would be lying, deceit, defamation, speaking maliciously about someone, and swearing falsely. All of these things God hates (and speaking the names of other gods)! Not the use of words that humans consider "bad" or "offensive".