An additional nuance is that I've often seen "lapsed" used as a self description of people who are somewhat regretful about no longer practicing their faith. W

An additional nuance is that I've often seen "lapsed" used as a self description of people who are somewhat regretful about no longer practicing their faith. Whether as a self description or used by others, it generally carries a connotation that having left the faith is a negative thing. I agree that "former" is a more neutral term.