Here's something with which to cheer your children: Jewish, Muslim, and Christian fundamentalists will gain significant ground against their liberal and secular counterparts by 2050, even surpassing them in some cases. This is the view of Eric Kaufmann, a fellow of the Belfer Centre which is part of the J F Kennedy School of Government at Harvard University.
The increase in the size of a religion's fundamentalist population can change the local and even national politics of a country, according to Kaufmann, and demographic change can threaten a state's security because it produces a larger pool of potential religious militants. Kaufmann suggested that while most fundamentalists are not militant, all militants are fundamentalists.
While the overall total fertility rate (TFR) is on the decline, the TFR among those on the more religious end of the spectrum remains well above replacement. American Jews have a very low TFR of 1.43, but within this group, ultra-Orthodox Jews (Haredim) stand out as exceptionally fertile: they increased their share of American Jewry from 7.2 to 9.4 percent during 2000–2006 alone. In Israel, the Haredim had a TFR of 7.61 in 1996 while other Israeli Jews' TFR stood at just 2.27. This will enable the Haredi to form a majority soon after 2050. Kaufmann hypothetically asked a lecture audience he addressed to consider the impact this could have on the peace process since the orthodox and Haredim are particularly attached to Jerusalem — where they are a majority — and to the holy places and "promised" land of the West Bank.
You can read a full summary of Kaufmann's views here: http://belfercenter.ksg.harvard.edu/publication/18824/demographic_projec...