Since Christianity believes God is Creator of humanity (male and female), and since Christians hold that God instituted marriage from the beginning (i.e. one man and one woman); then, all matters sexual and marital are primarily under the nomenclature of the “religious” for Christians. No matter what others think or believe, a biblical Christian will agree that if proper use of physicality and sexuality falls under the rule of God, then everything considered an aberration of that physicality and sexuality also falls ultimately under the religious domain. When one chooses to exercise his sexuality in accordance to biblical codes of ethics and morality, then that one has exercised his religious freedom. Likewise, when one who is not Christian chooses to exercise his sexuality in discordance to biblical codes of ethics and morality; then that too is primarily an act of moral free will, and so, should receive classification as a religious matter. By this, it is concluded that both marriage (homosexual or heterosexual) and moral matters (sexual activity) are primarily religious matters–that is, they are matters primarily categorized under “church,”—from the biblical Christian perspective.
As such, Christian marriage is—for the Christian—a purely religious act. Civil marriage, as recognized and “licensed” by a government, may or may not meet the definitions set forth by the biblical and historical (2,000+ yrs.) definitions of Christian marriage. Where definitions of Christian marriage and civil marriage diverge, the Christian should side with definitions of Christian marriage, even to the disregard and rejection of civil marriage.
In plain application, if the State will not recognize the Christian definition of marriage, nothing Christian is lost to the Christian. We can still have Christian marriages before God. If the State will not license (or threatens to revoke licensure and/or tax exemption) Christian ministers to perform marriages recognized by the State, because the Church defines marriage in a way not approved by the State, then nothing Christian is lost to the Christian! Lose the State license; submit to the tax. Render to Caesar what is Caesar’s. Give to God what’s His. This is not to say Christians should not obtain a marriage certificate via their local court; it is to say a Christian pastor may not be the one to issue the license/certificate.
This is religious freedom.