Personal Life Dealbreakers for Academic Jobs There are certain academic jobs such as Baylor or BYU that require a certain way of life. BYU, for instance, requires one to adhere to the Church Educational System Honor Code and Baylor typically requires a letter of recommendation from your Minister/Rabbi (their words) with one's application. For example, being in a gay relationship would be enough to be expelled from BYU.

These require a certain type of personal life choices and lifestyle, and, while they are very religious schools, there are other possible dealbreakers at secular universities. For example, secular schools have retracted offers due to the fact that the applicant for a faculty job is on the sex offenders registry.

There's a huge amount of gray area between these two data points that I have. Where is the line drawn on how much one's personal life matters at a secular school? What would have to be publicized about a faculty member's or applicant's personal life in order for the person to have an offer rescinded or tenure revoked?  Is it only about the research/teaching/service, or is there any examination on the person's life if that common knowledge in the community?

My question is mainly about the United States.
I am not a lawyer, so take this with a grain of salt.

In the US it is illegal to take information about a candidate's membership in a protected class as a basis for hiring or firing, except in circumstances where that information concerns what the law calls a "bonafide occupational qualification." 

The idea is that certain kinds of employers get to discriminate in ways that would otherwise be illegal because of their status as private entities dedicated to a particular mission. For instance, a Jewish synagogue can discriminate against non-Jewish applicants when it is hiring a rabbi. If the state prosecuted synagogues for religious discrimination because they only considered Jewish candidates, this would effectively be the state saying that Jewish Synagogues can't exist. 

So, in certain kinds of religiously affiliated schools, it is legal for the school to hire only members of a certain religion based on the same principle. But this only holds if membership in the religion is an explicit, advertised condition of the job, i.e. if the school is dedicated to being a school exclusively consisting of members of that particular religion. 

Most religious schools in the US are not actually like this--for instance there are dozens of catholic schools in the US which are open to students and faculty of any religious tradition, or no religion at all. Schools like that are not allowed to discriminate on the basis of religion, because clearly at such schools membership in the religion isn't a "bonafide occupational qualification".