Updated: Dec 15, 2020
By Luke Lancaster
The first example of a mortal sin comes from the Gospels, where Christ says, “Whoever denies me before men, I also will deny before my Father who is in heaven” (Mt. 10:33). Jesus was saying that, if you claim to be His friend, you better not tell others that you have never heard of Him. That would be a deeply betraying thing to do. He intensifies this by saying that, when you die and are judged by God, He would deny that He knows you at all, meaning that you’d probably go to Hell. Jesus would treat you as you treated Him: Not as a friend, but as a nobody. Now, Jesus was known for hyperbole, such as when He said that we must pluck out our eyes if they cause us to sin. Was Jesus just using strong language about denying Him, but didn’t actually mean it literally? The context of this passage shows this to be false, for He speaks in no uncertain terms about Hell: "And do not fear those who kill the body but cannot kill the soul; rather fear him who can destroy both soul and body in hell” (Mt. 10:28). You really can go to Hell for denying Christ in a serious way. Or as Paul says, “…if we deny him, he also will deny us” (2 Tim. 2:12). This is something that two of Jesus's own disciples would do: Judas and Peter. Both were in relationship with Christ. Both would sin venially at various points, but those never would've made Christ say to God, "I don't know them." It was the night of Jesus's arrest where they did something serious enough to shatter their friendship with Him. One denied Christ in his actions gravely, and the other denied Him through his words gravely.