Atheism and interfaith marriages
Given that: atheism is significantly less appealing to women, atheists are a minority in many parts of the world and that people tend to marry people with similar values or who resemble their parents or themselves; this would suggest that male atheists may find it more difficult to find prospective female partners for marriage. And of course, militant atheism might make matters even more difficult.
Atheists have a lower marriage rate than the general population (see: Atheism and marriage).
Furthermore, the Bible teaches Christians not to marry a non-Christian (The Bible also teaches a believer to stay married to a non-believer if you are already married).
In addition, interfaith marriages often have greater marital friction and interfaith marriages historically have had higher rates of divorce. According to a Washington Post article, "According to calculations based on the American Religious Identification Survey of 2001, people who had been in mixed-religion marriages were three times more likely to be divorced or separated than those who were in same-religion marriages."  Therefore, it would not be surprising if atheist/theist marriages also have increased marital friction and higher rates of divorce since these two worldviews are so different.
Unattractiveness of many atheists as potential marriage partners to theists
See also: Views on atheists
Atheists have a reputation for being arrogant, angry, socially challenged, immoral, uncharitable, cowardly and engaging in profanity, so their attractiveness as a potential marriage partner is greatly diminished (see: Atheism and arrogance and Atheism and anger and Atheism and social intelligence and Atheism and morality and Atheism and uncharitableness and Atheism and cowardice and Atheism and profanity).
For more information, please see: Views on atheists
Secular Americans and interfaith marriages
No doubt partly due to atheist men significantly outnumbering atheist women and the fact that atheists lean towards the liberal/left end of the political spectrum, the NY Times reported that "Secular Americans welcome the rise of interfaith unions as a sign of societal progress."
Prominent atheists whose wives believe in the existence of God
- Interfaith marriages are rising fast, but they're failing fast too, By Naomi Schaefer Riley Sunday, June 6, 2010
- Interfaith Unions: A Mixed Blessing By NAOMI SCHAEFER RILEY, New York Times, Published: April 5, 2013
- David Silverman
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