Real US church with a long history, prominent historic members (John Adams and family) and a rather open attitude towards the existence of God/gods: the Unitari

Real US church with a long history, prominent historic members (John Adams and family) and a rather open attitude towards the existence of God/gods: the Unitarian-Universalist Church. My agnostic childhood best friend sends her daughters to various youth programs there, and she and I are both recovering Southern Baptists (I went a more middle road: Episcopalian). She really likes their relationship and sexuality education series for teens.