Marriage is not an issue of equality. The Church and State (civil government) have the right and the obligation to protect and support both marriage and the family. Both depend on each other and both serve the common good of the Church and the State. Society is best served by marriage and family.
Equality is not absolute. While we are all equal in the eyes of God regardless of our age, gender, intelligence, economic status, etc., we are not all the same in terms of the gifts, talents, blessings, experiences, etc., that we have been given. Saint Augustine taught that EVERYONE (all men & women) are given SUFFICIENT GRACE to be saved, but it only becomes EFFICACIOUS to those who ACCEPT and COOPERATE with it. Human nature (body & soul; rational intellect & free will) is the same for everyone. All human beings enjoy the right to life and the right to access to necessary goods. We are endowed by our Creator inalienable rights, like the Right to Religious Liberty (Freedom of Religion) and the Right to Free Speech, Freedom of Assembly, Freedom to Defend oneself, one's family & possessions, and one's country.
If marriage is redefined and reinterpreted to allow same-sex unions to become recognized as marriages, it is not a matter of civil or human rights. Marriage is a special bond between one man and one woman. As a sacrament, it requires that both bride and groom intend to enter a FAITHFUL, PERMANENT and God-Willing FRUITFUL union. Since we live in a pluralistic society where no one religion has governmental priority, many claim that civil marriages should in no way be influence by Judaeo-Christian values and beliefs. Unfortunately, this is not true. Pagan Greece and Rome, Egypt and all ancient and modern cultures and civilizations realized the importance and the necessity of preserving marriage. While polygamy had been tolerated long, long ago, it soon was abandoned and condemned as being detrimental to the family. One man and one woman covenanted for life.
If same-sex marriages are universally allowed across America and across the world, then the family will be at higher risk of disintegration. If two men or two women are allowed to marry each other, there is no legal or logical rationale to prevent multiple spouses (polygamous marriages) or even incestuous unions from occurring. For if the natural law no longer applies that marriage is between one man and one woman, then it must be open to several men and/or several women and of any age as well. Why restrict marriage between adults if the requirement of opposite gender no longer applies? What about consanguinity? What is there to stop or prevent someone from marrying a sibling, first cousin or even parent-child relationship? If the natural law is not respected in one area and dimension, it can redefine and recreate a new reality not confined by tradition or reason.
To deny polygamous or incestuous marriages violates no rights and neither does the restriction of same-sex marriages. Morally and spiritually speaking, the Catechism makes the distinction that same sex orientation/inclination is disordered but only sex activity outside of marriage is sinful and immoral. Sadly, many heterosexual couples co-habitate and live in sinful concubinage. There are others who are civilly married but not validly in the sacrament of Matrimony due to prior bond or some other significant impediment. That these relationships exist does not justify them. Discrimination is when people are mistreated and denied basic human rights. Not everyone is meant to be married but everyone has a right to live, a right to self-preservation, a right to access to food, clothing, shelter, employment and education. Marriage is natural estate upon which the family is built. Like the Church and the State, the Family is built on individuals and on the holy estate of marriage.
Tax exemptions, insurance benefits, etc., are prudential judgments which can be discussed and debated as to whether or not they apply to traditional marriages and families only or if they can be extended or amended for same-sex relationships. The institution itself, however, of MARRIAGE, is not a man-made entity. Even the Church and the State cannot redefine or recreate it.
Why is there even such a thing as a marriage LICENSE? Like a driver's license, it is not automatically given to anyone and everyone. One must request it and one must present documentation showing their eligibility. That means the Church and the State have the authority to govern and administer this vital estate for the common good of society at large and for the common good. Likewise, there are licenses for physicians, ministers, et al. Some authority must oversee and evaluate the candidates and judge their suitability and then authorize them. The same applies for marriage. Meanwhile, there is no reason and no room for nasty epithets, insults, or hateful remarks on either side of the public debate. Vilifying those who uphold and defend traditional marriage as if they were bigots is not justified. Privileges are not the same as rights. Every human being enjoys human rights by virtue of their human nature, from the unborn in the womb to the sick and dying. Privileges, like marriage, however, are under the care and protection of Church and State for the sake of the common good.