The second example of a mortal sin in Scripture we shall consider is apostasy. This is where a believer, who started living a totally new life of thoughts, words, and actions, decides to go back to his previous way of living. St. Peter said in 2 Pet. 2:20, “…if, after they escaped the defilements of the world through the knowledge of our Lord and Savior Jesus Christ, they are again entangled in them and overpowered, the last state has become worse for them than the first.”
This is saying that a Christian who has stopped living a life of sin and “escaped the defilements of the world” could start to “again” go back to his old habits. If that occurs, St. Peter says, they are placed back into the category of “unbelievers,” and not only that, but are “worse” than they used to be. Why? Because “the sow is washed only to wallow in the mire” (2 Pet. 2:22). A pig rolls around in the dirt of sin, then is washed, but then leaves the clean lifestyle and goes back to the mud. That is the image of a Christian who could go to Hell.