Now, as some of you reading this may know, I am not a religious man, at all, infact, one could say that I have a very negative view of religion, but enough with that, to the point.
The general idea with mortal sin, is that some sins, such as murder, are much greater then other sins, and unforgivable in Gods eyes, by perpetrating these sins, you are guaranteed a place in hell, this, is bullshit. The words 'mortal sin' do not occur once within the bible, not at all, wanna check? be my guest (biblegateway.com). According to the bible all sins are equal in the eyes of God, there are no lesser sins, or greater sins. Mortal sin, is a concept, that was invented by the catholic church, simple as that.