WACO, Tex. — Battles for acceptance by gay and lesbian students have erupted in the places that expect it the least: the scores of Bible colleges and evangelical Christian universities that, in their founding beliefs, see homosexuality as a sin.

Decades after the gay rights movement swept the country’s secular schools, more gays and lesbians at Christian colleges are starting to come out of the closet, demanding a right to proclaim their identities and form campus clubs, and rejecting suggestions to seek help in suppressing homosexual desires.

Many of the newly assertive students grew up as Christians and developed a sense of their sexual identities only after starting college, and after years of inner torment. They spring from a new generation of evangelical youths that, over all, holds far less harsh views of homosexuality than its elders.

But in their efforts to assert themselves, whether in campus clubs or more publicly on Facebook, gay students are running up against administrators who defend what they describe as God’s law on sexual morality, and who must also answer to conservative trustees and alumni.