Gershom Gorenberg makes the case. Here is the key graph:
For Israel’s Jewish majority to be free to debate and explore [the question of what it means to be a Jew, an] essential step is to disestablish religion. Today, Jews can marry or divorce inside Israel only through the state rabbinate, a government bureaucracy. Rabbinate officials usually belong to the ultra-Orthodox community, which segregates itself from wider society. State funds also subsidize Orthodox and ultra-Orthodox educational institutions. In turn, most Israeli Jews feel alienated from state-backed Judaism. A young Israeli is more likely to get interested in matters spiritual during the standard post-army trip to India than by visiting a synagogue near home.
So disestablishing religion would not only protect the rights of non-believers. It would protect Judaism from the state. As Tulane University sociologist of religion Brenda Brasher argues, the United States is the most religious country in the West precisely because of its sharp separation of church and state: Since religious institutions must survive by attracting people to come through their doors, the United States has become a hothouse of religious innovation and variety. In Israel, likewise, once the state ceases to fund and sanction specific varieties of religion, Judaism is likely to flourish, invite wider interest and take new forms.
This is not only a problem in Israel. It is a problem in a number of countries with a historic Roman Catholic tradition, in which the Catholic Church hangs on to the residual privileges of being the state church. It is a problem in England, in which the Anglican Church, to its own detriment, remains the religion of the state, but less and less, the religion of the common man. It is a problem which involves Orthodoxy in countries like Russia and Greece, in which the old ways of an alliance between throne and altar have not died out, but take new and ever more tawdry forms.
The sooner Judaism and Christianity are completely disestablished around the world, the better. The transition will not always be easy. The disestablishment of the Catholic church and the historic Protestant churches in Germany is turning out to be a long, drawn-out affair, with precious little evidence that the churches are learning to operate in an environment in which a person’s faith is not necessarily passed on to them by their parents, but something that each person must freely choose, or not.
The Baptists have a saying, “God has children, but no grandchildren.” Like it or not, that is true, today more than ever.