Abandoning or renouncing of a religion by a person as a formal act is called “apostasy,” *1 and almost every religion has its own way of how to deal with this. Some ways are harsher than others.
That being said, I have never understood the concept. I can remember being jokingly teased by my parents that they will renounce me in the newspapers, whenever I did some silly, mischievous thing. I remember sitting on the sofa, with a half-guilty half-confused expression on my face, thinking, “WTF does that even mean!?” My instincts were telling me that it was a bad thing, but semantics and logic were completely off. My brain was saying “and ... that will do what?! It will not change the fact that I have their blood and that they are my parents.”
I have similar feelings about many things: being human, being an Earthling, being a member of any group that has certain knowledge about something. If you cannot forget it, and if you cannot change it, you still belong there, whatever you said or do.
Take religion, for instance: if believers truly believe that God’s properties include omnipresence and omnipotence, that would mean that God is a part of everything and everyone, meaning that, even if you renounce it, it will still be there (as it is part of everything).
I hope I am not making this too confusing. What I am trying to say is that, if they truly believe in God, they would realize that no one can leave the entity they worship, and, therefore, there is no need for punishment. Also, if they still believe in punishment, they are the ones who should be punished, as they do not believe in their God enough to realize that it is omnipotent and omnipresent.
The foundation of our relationship to God is the free will; therefore, we should be free to decide what we want to do with our lives. If you do not have free will, and if you must behave as part of the machine, no one can blame you for your actions. There is no purpose of faith, morality, or punishment.
A religion that you cannot leave is not a real religion, if you do not have a choice, and if you are forced to do it, then it is lacking the main element — trust or faith. If there is no trust, believing does not have a purpose.
If I say, “It is an organization that prevents their members from leaving the organization by using fear, terror, and punishment,” what is the first thing that pops into your mind?
There are many organizations that have the same structure, although they call “apostasy” by different name. For instance, the mafia is famous, among other things, for not allowing their “soldiers” to leave or — even worse — to switch sides. In military jargon, apostasy is call “desertion” (abandonment of duty or post) *2, and during a war, the punishment is the same as in some religions.
In this light, can we argue that religions that punish people for apostasy are actually “military” organizations that are in a constant “war” of expansion, a “war” designed to gain as many affiliate members possible, in order to gain a monopoly over the “market”?