The First Amendment to our Constitution bids the government to “make no law
respecting an establishment of religion, or prohibiting the free exercise thereof.” It is pretty clear what that means. For many years British civil servants and politicians as well as professors at Oxford and Cambridge universities needed to be Anglicans. Those jobs were not open to members of other religious persuasions. In Germany until World War I, only Christians could be civil servants, including university professors. Jews could not have those jobs unless they converted to Christianity.
No one in the United States today, even folks who keep saying that ours is “a Christian nation,” proposes that we should demand of all government officials that they be Christians.
But surely the question of religion and politics goes beyond that. The Catholic Church is refusing to allow its members to have their birth control paid for by insurance companies. Members of various Christian denominations refuse to support equal marriage rights for gay people on the grounds that the Bible describes homosexuality as an abomination. Many people oppose abortion on similar religious grounds. Teachings of specific religions, they think, may be used as the justification of legislation. All of us, even those who do not share the religious belief in question, may be forbidden to practice what one or another religion condemns.
Underlying these controversies is a serious disagreement about religion. Implicit in the First Amendment is the belief that religion is a private matter. A Christian may believe very firmly that Jesus Christ was the promised Messiah and died for our sins. A Jew may praise Jesus as a notable prophet but insist that the Messiah's return is still in the future. But, because religion is a private matter, neither of them can impose their belief on the other.
When you enter grade school you learn to add and subtract. Your teacher teaches you that 2+2 = 4. If you don't want to accept that, you get punished with a bad grade. The belief that 2+2 = 4 is not a private matter. You have no choice in it; you must accept it because it is true.
Not so, for instance, your preferences in ice cream flavors. I like chocolate, you like vanilla. It would be totally bizarre if I forced you to eat chocolate because chocolate is, I think, “objectively” the best ice cream flavor. If I tried, you would point out to me that one's taste in ice cream is private, is subjective. Different people are entitled to their own tastes in food.
But most followers of one religion or another, whatever they may say, do not accept that religion is a private matter in precisely that sense that you may not impose your religious beliefs and the conduct these beliefs demand or forbid on anyone else who has different beliefs. The Pope does not believe that Catholic theology is something that you may accept or reject. For Jews the Law is a divine gift that we must follow. The beliefs of different religions are not merely subjective. They are not private.
When Mormons baptize people posthumously, they are telling us that Mormonism is the only true form of Christianity. Catholicism, different varieties of Protestantism are all idolatry. What is more they don't regard this as just some personal belief which others may share or not. They know that that is absolute truth. The Catholic Church – not necessarily its members – know for a fact that birth control is sinful. Evangelical churches know the same about gay sex. And all of them know for fact that Jews and Muslims are going to burn in hell.
The First Amendment demands that we treat all religious beliefs as purely personal and subjective. It makes no more sense, the First Amendment tells us, to force our religious beliefs on others than it would be to force on them our tastes in ice cream. But most religious people – except perhaps some Unitarians or Quakers – do not believe that about their religious beliefs. For many religious persons their religion is the bedrock on which their life rests. Make those beliefs subjective and, in some sense, arbitrary like tastes ice cream, and their lives would have no foundation. For that reason, religious persons hold on for dear life to the belief that their religion is the true and only one.
So when in the course of the current electoral campaigns, Catholic bishops fuss endlessly about birth control, and other candidates fulminate against abortion or gay marriage on religious grounds, they seriously challenge the First Amendment with its non-establishment clause. It makes us realize that our dedication to the First Amendment has always been conflicted. Some people are serious about regarding religious beliefs as private. Most religious people regard religious beliefs other than their own as private, subjective, and arbitrary – if not completely mistaken. But the First Amendment does not apply to their religion. It is literally God's truth. Their dedication to civil rights is clearly qualified.
This is not intended to be a condemnation of religion. But it is important to understand the Rick Santorum phenomenon: their religious faith--not that of others--is as true and as important as anything in the lives of seriously religious persons. The First Amendment holds for all religions--except their own.