Well in a short historical overview. The narthex is the room or hall in a church that separates the outside world from the main room that is the church with its altar. When the Romans came up through Europe they built the narthex in order to convert Pagans to the Christ God. The Romans did not like the fact that just any infidel could walk into the church of god. So they created the narthex to buffer out what they didnít want. This room was made so that when pagans attended mass they would not be apart of Gods children, instead they would witness mass from the back through a window in the narthex, until they have proven themselves, and maybe one day they would be granted communion and then they could enter. The narthex gave the opportunity to outsiders to look in and choose whether they want to commit to learning and walk in, or just plane walk away. Eventually all those who walked away walked away with a target on their head.
The Narthex is a place of decision.