This is a Catch 22 situation, because the most effective way of changing a heterosexual's beliefs about homosexuality is for them to befriend a homosexual. Adult sexual orientation is essentially unchangeable . The potential for Homosexuality is determined genetically in most or all people at the time of conception. Sexual orientation appears after puberty but is established by early childhood. Since sexual orientation is not a matter of choice, homosexual and bisexual feelings are not sinful.
Actions are a different matter.
History has shown that whenever a minority group becomes organized and demands equal rights, that they eventually attain equality. Women achieving the right to vote and to enter into any profession. Interracial couples seeking the right to marry If past precedents hold, then gays and lesbians will eventually attain equal rights, including the right to marry. By the year 2010, mainline Protestant denominations will probably catch up with liberal faith groups and will accept sexually active persons of all sexual orientations as members and clergy. They will eventually approve of same-sex commitment or union services and adoption by homosexuals.