I understand why some people would think it was made purely on reasons of faith. I agree with your statement that this is one of those situations where faith can be included. This area called the Mormon Trail is so called because in the early 1900s the Mormon Church was hired by the Canadian government to come and settle this area and build the irrigation canals and so on.
To this day, the population of this town is probably 65% Mormon. But as I said, there are more Mormons who are staying in the Lethbridge riding than would be in this riding. In both ridings they'd be fewer than 10% of the population.
The Mormon Church itself did not become involved in this question. It was the case that they said their religion or faith happens to be part of what unites them as a community of interest, but it doesn't exclude those who aren't members of that church. They still feel part of that community of interest as well.