Adults in religiously mixed marriages are, by and large, less religious than their counterparts who are married to spouses who share their faith. They attend religious services less often, pray less frequently, tend to be less likely to believe in God with absolute certainty and are less inclined to say religion is very important in their lives.

People in religiously mixed marriages also discuss religious matters with their spouses less frequently than those who are in religiously matched marriages. Religion does not, however, appear to be the source of much strife in mixed relationships; while those in mixed marriages report somewhat higher levels of disagreement about religion, majorities nonetheless say religious disagreements are not common in their marriages.

When asked about what kinds of things are important for a successful marriage, 44% of adults say shared religious beliefs are “very important.” By this metric, shared religion is seen as more important for a good marriage than shared political attitudes, but substantially less important than shared interests, good sex and a fair division of household labor. There are, however, significant subsets of the population who place a higher priority on religion within marriage; most people who are highly religious themselves say shared religious faith is critical to a good marriage, and women are much more likely than men to say the religion of a prospective spouse is likely to factor prominently in a decision about whether to get married.

The data also show that when parents attend religious services, they mostly do so with their children – especially if they are in a religiously matched marriage. Religiously affiliated parents married to spouses who share their faith also are more likely than intermarried parents to pray or read scripture with their children.

The remainder of this chapter explores attitudes about and experiences with religion in family life.

Religiously intermarried people are generally less religious than those married to spouse with same religion

Religiously affiliated people in mixed marriages tend to be less religious than those who are married to spouses who share their religious identity. Among Catholics married to other Catholics, for instance, seven-in-ten are highly religious, according to an index of key measures used to determine levels of religious observance in the Religious Landscape Study (including frequency of worship attendance, frequency of prayer, belief in God and self-described importance of religion in one’s own life). By comparison, only about half of Catholics married to non-Catholics are highly religious.

Of course, it is impossible to know for sure the direction of the causal arrow in the relationship between religious observance and religious intermarriage. Marrying someone from a different faith might serve to make people less religious. Alternatively, it could be that people who are not particularly religious to begin with are more likely to marry a spouse with a different religion. Or it could be some combination of both factors.

In any case, while intermarriage is linked with lower rates of religious observance among those who are affiliated with a religion, there is little evidence that the relationship goes in the opposite direction for those who are religiously unaffiliated. That is, being married to a religiously affiliated spouse seems to have little impact on the religiosity of religious “nones.” Just 13% of religious “nones” married to a religiously affiliated spouse are highly religious, which is only modestly higher than the 9% of “nones” married to fellow “nones” who are highly religious.

For a successful marriage, shared religious beliefs prized about as much as adequate income, less than sex and shared interests

Overall, 44% of U.S. adults say shared religious beliefs are “very important” for a successful marriage. By that metric, religion is seen as about as important for a successful marriage as is having an adequate income or having children, and it is considered less important than having shared interests, a satisfying sexual relationship or an equitable distribution of housework.

Among married people, the survey finds big differences in the perceived importance of religion depending on the nature of one’s marriage. Nearly two-thirds of religiously affiliated respondents with spouses who share their faith (64%) say shared religious beliefs are key to a successful marriage. Far fewer married people in interfaith relationships see shared religious beliefs as central to a successful marriage.

The data also show that among those who are highly religious – including both married and unmarried respondents – shared religious beliefs are prized in marriage almost as much as shared interests and about as much as a satisfying sex life and sharing household chores. Far smaller shares of those who are not highly religious see shared religious beliefs as essential for a good marriage. Having children also is seen as critical for a good marriage by more of those who are highly religious than those who are not.

While nearly half of married people say shared religious faith is crucial for a successful marriage, just 27% of married adults say their spouse’s religion was, in fact, a “very important” factor in deciding whether to marry them specifically. Roughly a third of religiously affiliated adults who are married to someone of the same faith (36%) say their spouse’s religion factored prominently in their decision to marry, while far fewer intermarried adults – and just one-in-twenty religious “nones” married to fellow “nones” – say the same.

Among those who are not currently married, the survey finds the religion of a potential spouse is more important to women than it is to men. Nearly four-in-ten women say their potential spouse’s religion would be a “very important” factor if they were considering marriage, while just 26% of single men say the same.

Not surprisingly, the data also show that the religion of a potential spouse would be far more important to highly religious people than to single people who are not highly religious. Still, even among the highly religious, roughly a quarter say the religion of their prospective spouse would be only “somewhat important” to their decision, and one-in-five say it would be “not too” or “not at all” important.

Among both men and women, more say women are the more religious half in marriage

Roughly six-in-ten married people say they and their spouses are about equally religious. This includes about three-quarters of “nones” married to spouses who are also religiously unaffiliated and nearly two-thirds of religiously affiliated adults married to a spouse from the same religion. Only about half of religiously affiliated adults married to someone from a different religion (46%) say they and their spouse are equally religious, and just 36% of those in a marriage combining one religiously affiliated spouse and one religious “none” say both spouses are equally religious.

Among those in this latter type of relationship, it is typically the religiously affiliated spouse who is described as more religiously observant than the unaffiliated spouse. The data also show that in marriages in which one spouse is more religious than the other, wives generally are seen as more religious than husbands. About one-third of married women say they are more religious than their husbands, while a similar share of husbands say their wives are more religious than them. By contrast, just 8% of women and 10% of men say the husband is more religious in their marriage.6

Most religiously affiliated people with spouses who share their religion say they attend religious services with their spouse. Attending services at a house of worship together is far less common among people married to a spouse from a different religion. And among married “nones” whose spouses are also religiously unaffiliated, most say they rarely or never attend religious services at all.

Religious disagreement relatively uncommon, even in intermarriages

Within marriages, religious discussion is most common among religiously affiliated adults who have spouses affiliated with the same religion. Nearly eight-in-ten (78%) in this group say they talk about religion “a lot” or “some” with their spouse; religious discussions are less common among those married to a spouse with a different religion (or no religion) and among religious “nones” married to fellow “nones.”

Religious disagreement is most common in religiously mixed marriages; for example, one-third of those in marriages pairing a religious “none” with a religiously affiliated spouse have at least some disagreements about religion. Still, in all kinds of marital combinations, religious discord is the exception rather than the rule; majorities in all types of pairings say they disagree with their spouse about religion “not much” or “not at all.”

Intermarried parents participate in fewer religious activities with their children

Most parents attend worship services at least a few times a year, and their children typically attend with them. About two-thirds of all parents of children currently under 18 (65%) usually attend worship services with their kids, including roughly eight-in-ten evangelical (83%) and Catholic (78%) parents and two-thirds of mainline Protestant parents (67%). Religiously unaffiliated parents are less likely to attend religious services at all; roughly seven-in-ten (69%) say they seldom or never attend church (or did not answer the question about attendance).

Among married parents, those who share their spouse’s religious affiliation are among the most likely to attend worship services with their children (83%). Intermarried parents and “nones” married to other “nones” are less likely to attend religious services, but when they do, they also mostly say they take their kids with them.

Religiously affiliated parents married to spouses who share their faith are most likely to pray or read scripture with their children and to send them to religious education programs. They also are more likely than others to say they do volunteer work with their children, though the gaps between religiously affiliated parents married to a spouse of the same faith and other kinds of couples are relatively modest on this question.