The inalienable rights of all individuals, regardless of sexual orientation, must be upheld and protected by the legal system of a free society.
This includes the legal recognition of the right of those individuals who identify as lesbian, gay, bisexual, transexual, queer, and nonbinary to form legal marriages, with all of its legal and social consequences. Sexual actions and romantic relations between consenting adults are not the business of other individuals, of society as a whole, and, above all, of the government.
The government has no moral authority to discriminate between and among individuals based on sexual orientation and/or gender. Its nature and function is to protect individual rights regardless of whether its elected officials, or appointed agents, morally approve or disapprove of the individuals they protect.
Recognizing that ignorance and prejudice do exist and are antithetical to a decent and thriving human life, these are not the provinces of government action. If one aspect of political liberty is the free exercise of volition, then one is free to be mistaken, even if gravely so. Needless to say, there are a multiplicity of ways to engage such individuals by non-violent means in a civil society that do not violate their individual rights.