No we are not saying to anyone, including gays, that "you can join us." The Church is not a country club, where you join the membership. In our baptism we are joining Christ in his death and resurrection, and by the function of that event/act we become (members of ) a community---and not the other way around.
And, sorry to disappoint you with bad news, but yes, joining Christ is a one way street. You either transform/conform to Christ, or you did not join Christ. Trying to form God into your image and likeness and not to allow to be formed into God's image and likeness is the worst form of idolatry in any religious practice. Good luck to you ...