nonsectarian

/ˌnɑnsɛkˈtɛəriən/

You can describe something as nonsectarian if it's not connected or affiliated with any particular religious or political belief.

A college is nonsectarian if it isn't associated with a religion or church, and a Sunday school class that teaches all religions is also nonsectarian. Something that's sectarian follows the rules of a particular group or sect, and it's the Latin word secta that's at the root of both sectarian and nonsectarian. The literal meaning of secta is "a way or a road," and its figurative meaning is "a following, school of thought, or religious group."

Definitions of nonsectarian

1. adjective

   not restricted to one sect or school or party
   “religious training in a nonsectarian atmosphere”

   “nonsectarian colleges”

   synonyms: unsectarian

   ecumenic, ecumenical, oecumenic, oecumenical

   concerned with promoting unity among churches or religions

   interchurch, interdenominational

   occurring between or among or common to different churches or denominations

   nondenominational

   not restricted to a particular religious denomination

   undenominational

   not bound or devoted to the promotion of a particular denomination

   antonyms:

   sectarian

   belonging to or characteristic of a sect

   denominational

   adhering or confined to a particular sect or denomination

   narrow-minded

   rigidly adhering to a particular sect or its doctrines