In the religion in SnK, they worship the walls as their protectors and a number of times say that the walls were put there by God. The walls are also at least once referred to as Goddesses, though that is from subtitles and may not be entirely correct. Is this supposed to be based off of or mirror any real-life religion? Have the creators made any comments about this?
Although I can't find a source stating this, I presume this might be based on the Jewish religion. In the Jewish religion there is the Kotel. This is a old wall located in Jerusalem which is used for prayer.
The Western Wall, Wailing Wall or Kotel is located in the Old City of Jerusalem at the foot of the western side of the Temple Mount. It is a remnant of the ancient wall that surrounded the Jewish Temple's courtyard, and is arguably the most sacred site recognized by the Jewish faith outside of the Temple Mount itself. source
I feel like they refer to all real life religions. Since AoT people have no real history of our time, they slowly created their own religion to explain the walls and humanity (like Adam and eve).
I don't tend to Wikipedia every answer. In this case this is a personal opinion with which I back up with Armin when he is called a heretic for his beliefs, like in Assassins Creed where they always go on about their gods.