When working with engaged couples in premarital counseling, when I’ve asked the question, What do you think is the biggest looming threat to your living happily ever after together?, I usually hear replies that touch on issues like pornography, affairs, lack of healthy communication, having children, growing distance between spouses, conflict with in-laws, ESPN (!), and placing a higher priority on career pursuits than on the marriage, just to name some. All of these issues do hold the potential for threatening a healthy and lasting marriage. But they are not the most imminent threat.

Source: Jim Burns, homeword.com