SAMMAMISH, Wash. — Eastside Catholic prides itself on teaching acceptance. At the end of Crusader Way, by the school’s entrance, banners hang celebrating “relationships” and exhorting passers-by to “remember to take care of each other.” Students use a sign-language gesture to remind one another of the school’s emphasis on unconditional love.

But now the school is unexpectedly grappling with how it defines both love and acceptance. Last month, a well-regarded vice principal was forced to leave his job as soon as administrators became aware that he had married a man; in the weeks since, the suburban Seattle school has been roiled, first by protests in support of the vice principal, and then by the resignations of those who sought his departure. The chairman of the school’s board resigned last month, and on Tuesday, Eastside, a middle and high school with about 900 students, announced the resignation of its president.

The ouster of Mr. Z, as the former vice principal, Mark Zmuda, is known, comes amid a wave of firings and forced resignations of gay men and lesbians from Roman Catholic institutions across the country, in most cases prompted not directly by the employees’ sexuality, but by their decisions to marry as same-sex marriage becomes legal in an increasing number of states.