Blasphemy is one of those sins that has almost become a joke. When someone disagrees with either a very popular opinion or mocks something that another person greatly enjoys, there is a jokingly horrified exclamation of “blasphemy!” In fact, most people are only peripherally aware that true blasphemy is a sin at all. Rather like heresy, the actual meaning of blasphemy has been forgotten over time in the West. 

The word “blasphemy” has a very different definition today than it did in biblical times. Today, blasphemy is defined as any utterance that insults, mocks or is irreverent towards a deity or religion. Some argue that a remark only counts as blasphemy if it insults the actual deity or is deliberately offensive toward a religion’s followers. Still others claim that for a remark to be truly blasphemous, it must be made by a member or former member of the religion that is being insulted. Coming from a religious outsider, the comment is merely rude or insulting as the outsider cannot be certain that their insult will truly strike the religion’s beliefs. An insider, however, knows where to hit to make it hurt.

As is the case with a number of Christian teachings, the modern definition of blasphemy is often retroactively applied to the teachings found in the Bible. There are, however, innumerable problems with placing a contemporary concept on ideas that are multiple millenniums older. This is especially problematic with blasphemy as blasphemy against the Holy Spirit is seen in Christianity as the only mortal sin. Anything else can be forgiven except that. 

If blasphemy is any irreverent remark made about a religion, many Christians are naturally terrified that they have accidentally committed the one unforgivable sin. Did that stupid joke they made after a few too many drinks and a long week really damn their soul for the rest of eternity? Have they blasphemed the Holy Spirit without realizing it? The broad definition of blasphemy in the modern world leaves a great deal of room for accidental blasphemy. The biblical concept of blasphemy, however, is quite different.

The word “blasphemy” is found throughout the Bible. There is, however, no Hebrew equivalent. The English word “blasphemy” is based on the Greek blasphem meaning “to slander” or “to injure.” When looking at non-Greek manuscripts, the phrases that are usually translated as “blasphemy” involve words such as qalal or “curse,” gadap or “revile” and herep or “despise” when the object of the verb is God. In those cases, the curse was drawing the holiness and integrity of God into question. Blasphemy was something that threatened the fabric of the religious community, not a slightly off-color remark made after too many drinks on New Year’s Eve. 

Interestingly, blasphemy in the Bible does not refer only to a person’s words. Modern concepts of blasphemy involve almost solely the idea of speech. Biblical blasphemy, however, also includes a person’s actions. A person who deliberately insults God in speech is seen as much the same as someone who deliberately and willfully flouted God’s commandments. For example, David’s use of his position as king to rape Bathsheba and murder Uriah are sometimes translated as blasphemy.

Unfortunately for Christians, what counts as blasphemy is something of a source of debate. Likewise, the definition of what precisely is the unforgivable sin is also debated. Some people argue that intentional rejection of the Holy Spirit is the mortal sin. Others argue that would mean that conversions are impossible. Only Christians believe in the Holy Spirit. All other religions reject it. If there is no forgiveness or redemption for rejecting the Holy Spirit, then no one from any other religion could ever convert to Christianity. This flies in the face of the Gospel, the Great Commission and the many converts that Christ Himself won during His time on earth. Others believe that the mortal sin is knowing, deliberate and malicious insult toward the Holy Spirit while aware of the price of the sin. In this line of thinking, the mortal sin is knowing God and rejecting Him anyway. For better or for worse, there is evidence both for and against this idea in the Gospels as well.

Ordinary blasphemy is a bit easier to define using both tradition and examples found in the Bible. While one could argue that bad jokes do technically fall under the category of blasphemy, Scripture seems to favor the idea that blasphemy requires some preexisting knowledge that what a person is doing or saying is wrong and in some way insults God. To go back to the example of David, David was loved by God and in his position because of God’s favor. David then used what God had given him to break God’s commandments. Similarly, when a Christian curses God, they do so knowing that they are in the wrong, but they do so anyway. They know that they are both wrong in their actions and incorrect in their words, but they say it anyway. This is still not considered to be a mortal sin, but is sinful.

Blasphemy becomes something of a fuzzy grey area when it comes to drawing the line between where blasphemy ends and another sin begins. If deliberately acting against God is blasphemy, then would it not be true that almost any sin would be, by definition, blasphemous? There is no single answer to this question, but the best way to draw the boundaries of blasphemy would be to go back to the sins that would later be defined as blasphemy. Judging by the original Hebrew Old Testament, blasphemy involves cursing or reviling God. It implies acting or speaking with knowledge and with malice. As such, that joke you thought was funny may not edge into blasphemous territory, but it would probably be better to avoid retelling it in the future. Even if it is not blasphemous, learning to think before speaking is only ever helpful.