HE GREATEST BLASPHEMY against Judaism is probably something called Christianity. Think about it. The wrathful, jealous God of Moses--Yahweh of the ancient Israelites--is turned by Catholic apostasy into a Divine Trinity in which He becomes God the Father to a Son born of a Virgin crucified by His own Chosen People, and a Holy Ghost with tongues of fire that cause people to hear fishermen's voices. Christians owned both the Kingdom of Heaven on Earth which some called the Holy Roman Empire while the Jews would go into 2000 years of Diaspora. But a Prophet from Arabia would found his own religion with its own storied Ottoman Empire and its own ideas of Allah, who had neither Sons nor Daughters in its theology. Yet they all have a common spiritual ancestor in the Man from Ur, the Abraham or Ibrahim of the Judaeo-Christian-Muslim tradition.
But every organized religion is thus, in the ultimate analysis, a towering blasphemy of all the others. Heresy and apostasy are what one religion calls the things it does not believe in, which are often the very Creed and "infallible teachings" of another organized religion. More death and destruction has thus been visited upon humanity in the name of Religion than any other form of human vanity. Paradoxically, the converse is also true: Religion has been the source of the greatest good in human societies.
Man has been called the animal that invents and makes tools. I think Religion is a kind of tool -- like a moral compass -- that guides human beings when we strive "to do good" or "to discern the truth." In a moral dilemma deciding what the "morally correct" thing is to do is like trying to get to the peak of a mountain. But just like physical mountains, there are many trails that lead to the same mountain top. That is why over the centuries, people of all religions have come to the same basic moral positions of what is good and bad in human behavior, even if they still have wildly different ideas of what God or his Prophets might actually look like, or that you are even allowed to wonder about that.Religions, in other words, may violently disagree over what is God, but hardly ever in what is Good and Bad.
In modern consitutional democracies, Religious Freedom has made possible the peaceful, even fruitful, coexistence of the organized Religions. In fact without the coercive powers of the democratic state against all forms of religious intolerance and prejudice, religions would exterminate each other until only one were left standing in any given sphere of influence -- as indeed they have tended to do before Democracy was invented. Tolerance is an ancient human virtue, but Democracy, in particular the Separation of Church and State, is the institutionalization of that virtue.
In this sense, Democracy is a special kind of blasphemy, one that is directed at all religions. Democracy is a religion without a theology, a morality that miraculously secures the existence of religions with virtually any theology, by treating the practice of religion as an exercise in the freedom of speech and expression. This is accomplished in a democratic society by pushing theology into the sphere of the individual citizen's Right to Privacy, behind the wall of a person's right to hold any private opinion or belief and to express and practice it openly. Democracy protects Religion by making it a part of every's citizen's right to freedom of expression. The Freedom of Religion IS the freedom of expression.
It may seem strange that this very wall that protects our private religious opinions and our right to choose any Church in which to worship, is called the Separation of the Church and the State. But Democracy is an apostasy of all Religions because it makes Human Law the arbiter of "good" and "bad" in human behavior, at least with respect to the State's coercive and lethal powers. Democracy leaves Theology to Church and Synagogue and Mosque, yet firmly establishes its own effective jurisdiction over various parts of what someone once called "the moral continent of the conscience."
Thus, when anyone acts in the name of Religion, or claims to be exercising his or her Religion, such acts are exercises in the freedom of speech and expression. Whether such acts are moral and lawful or not, ought to be judged on that basis.
A second spiritual ancestor of all religions really ought to be Abraham Lincoln, whom we might update to the 21st century by quoting as follows: "The world cannot endure for long half-slave and half-free, for either we shall all be slaves, or we shall all be free."