It begins innocently – You talk about the events of the day, your interests, share funny stories. Pretty soon you’re discussing the passions of your heart and confiding in each other about the problems in your marriages. What began as an innocent friendship with someone of the opposite sex has quickly become an emotional affair. And if you’re not careful, it could mushroom into a full-blown physical affair.

Of course, most of us have friends of the opposite sex and never stumble into an affair. But it can be easier than you think to cross the line in those kinds of friendships. That’s why you need appropriate boundaries with opposite-sex friends and you need to guard your heart – and the heart of your marriage!

We live in a culture that is largely hostile to biblical truth, moral purity and marital fidelity. Our hearts are continuously bombarded by temptations from our human nature, our culture, and the devil himself. Here are three things you can count on:

1. You have a marriage relationship that is worth guarding with your life.

2. Living in a world that is largely hostile to healthy marriages, your hearts will come under attack.

3. You cannot survive these attacks on your own. You and your spouse must stand together against your common foe. You must guard your heart and guard each other’s heart. And you need others to stand with you over the long haul – Christians who share your desire for a divorce-proof marriage.

Men: It can be especially easy for you to begin capturing another woman’s heart without even realizing it. You may think you’re just having an enjoyable conversation with a coworker, but it may be the only attention that woman has had all week. Before you know it, your conversations move from friendly chatter to intimate subjects. We’re not suggesting men can’t have friendships with other women, but we are warning it can be easier than you think to cross the line.

Think of it this way: If this woman invited you into her house and the two of you were along, would the topics and conversation stay the same as they do in public or with other people? And here’s a word of advice for you guys: Trust your wife’s instincts in this area. If your wife suggests another woman is behaving inappropriately, she is probably right. Most women have radar, an innate alertness to nonverbal communication and an ability to translate body language into emotional facts. Your wife probably is able to see these things clearly. Regard it as a gift from God that will keep you out of danger.

Women: you need to know that for you, as well as men, adultery begins in the heart. Be careful you are not lured away from your marriage by a man’s tenderness, openness, warmth, personality, and attentiveness. When you sense that someone else is captivating your heart, when this attraction results in increased disappointment or frustration toward your husband, or when you begin to dwell on or act out your fascination, it’s time to confront the threat.

Here are several practical tips that will help you guard your heart in your friendships.

1. Dismiss and replace tempting thoughts. Don’t allow any unwholesome thoughts to make a home in your mind. If those thoughts enter your mind, it’s time to look away or leave the room. If you can’t leave, shift your focus away from that person by thinking of your spouse. Start praying for your spouse and your kids. Wrong thoughts don’t easily coexist with sincere prayer.

2. Don’t gaze too long into the windows of the soul. Eye contact in a conversation is good. But if you catch a look that is too intense, too engaging, or makes you uncomfortable, avert your eyes and resist that gaze. A deep gaze can stir something in one or both of you, something you don’t want stirred up. Save that eye contact for one person: your spouse.