An affair. It’s something that can destroy a marriage, a family, and all the lives connected to it. And it’s something we all hope will never happen to us. But here’s the harsh reality: An estimated 53% of all people will have one or more affairs during their lifetime. And when it happens, 70% of wives and 54% of husbands don’t even know their spouses have had an affair.

Infidelity isn’t something to be ignored – it is a threat to your marriage that you need to protect against. In fact, sexual temptation can be one of the most subtle and potentially destructive threats to your marriage.

Husbands and wives: here’s something you need to know. Men and women are usually drawn into an affair differently. For men, it’s about physical attraction. They’re typically captivated by the way a woman looks. For women, the temptation is more emotional. They’re usually lured in by a man’s kindness, attentiveness or affection. But there can also be exceptions to the rule. Sometimes women are tempted by a man they consider handsome, and sometimes men are enticed by a woman who is attentive and caring.

Here’s the reality: “Falling” into adultery rarely happens. Illicit liaisons don’t just pop up out of nowhere. They grow out of something that was once innocent and harmless. And healthy marriages don’t just go bad overnight. They erode over time through neglect and disinterest.

And adultery doesn’t begin in the darkness of a hotel room, in a secluded storeroom at the office, or in someone else’s bedroom. It doesn’t even begin with the first look or word or touch. For men and women, adultery begins in the heart. That’s why it is so important to learn how to guard your heart against these kinds of threats to your marriage.

Sometimes a man or woman is drawn away by the attention and interest of someone else because their spouse isn’t paying attention to and isn’t interested in him or her. When you stop pursuing and courting your spouse, you leave your spouse’s heart unattended and vulnerable to anyone else who shows interest in him or her. But a disinterested and inattentive spouse is no excuse for a husband or wife to turn to someone else to meet his or her needs. It only makes a bad situation worse and ultimately – more painful.

When a man or woman goes to bed with someone other than his or her spouse, they’re not only acting selfishly and wounding their own soul and marriage; they’re also wounding the person they’re with, soiling that person’s marriage or the future marriage God may be preparing him or her for. The damage is incalculable.

You probably wouldn’t travel a steep, winding mountain road in your car if there weren’t guardrails for safety. Guardrails are there for a purpose: to protect you and your car from plunging over the edge. In the same way, you need to establish guardrails in your life to keep you safe from the sexual temptations you will encounter on your journey. These four guardrails will help you guard your heart and marriage from the perils and pain of unfaithfulness. 

1. A strong relationship with the Father. Your ongoing intimate relationship with Father God is your strongest guardrail against sexual temptation. He has the best counsel. He knows exactly how men and women are wired – because He wired us. How you deal with your sexuality is of the utmost importance to God. The closer you stay to Him, the greater will be your access to His wisdom and counsel for resisting sexual temptation.

2. A cautious relationship with others of the opposite sex. We’re not talking about cutting off all contact with the opposite sex. We’re talking about being cautious and alert for temptation in these relationships and maintaining a margin of distance that will help you resist those temptations. Dismiss and replace tempting thoughts, don’t go out of your way to see or meet someone, be careful with physical touch and keep conversations general.

3. An open relationship with other Christians. Your Christian friends can also be a trustworthy guardrail of sexual purity in your life. You must be willing to lay aside anything that would hinder or rob you from allowing those people who know and love you to scrutinize your life. We need a group of trustworthy Christian friends to encourage us to remain pure, to edify us when we are struggling with sin in our lives, and who can help restore us to obedience when we have stepped over the line in some way.

4. A fulfilling relationship with your spouse. If you are emotionally or sexually thirsty, head for your own well, the well God has provided for you. Quench your thirst at your own fountain instead of roaming around looking for another. And make sure you anticipate and meet your spouse’s sexual needs. When you are full and satisfied sexually in your relationship with your spouse, neither of you will need to look elsewhere for satisfaction.

If you have already fallen into temptation in this area, do something about it now. It may be too late to escape the hurt and distress you’ve caused. But you can begin to make things right and heal the wounds. Break off the relationship you’re in. Confess to God and to your spouse. Seek counseling, and submit yourself to mature Christians to monitor your restoration. God loves you and He will walk you and your spouse through each step of the healing you need. There is hope for you. There is forgiveness. God has the power you need to be all he has called you to be. And he can help you guard your heart against further regret.

Stay alert, and remember: A guarded heart helps build a divorce-proof marriage.

Portions of this article were adapted from "The Great Marriage Q&A Book," Copyright 2006 by Dr. Gary and Barbara Rosberg, all rights reserved. Published by Tyndale House Publishers, Inc.,www.tyndale.com. To order this resource or to find our more about Dr. Gary and Barb – Your Marriage Coaches, visit www.drgaryandbarb.com or call 1-888-608-COACH.

Married over 30 years, the parents of two adult daughters and four grandchildren, Dr. Gary and Barb Rosberg, your marriage coaches, have a unique blend of insight and wisdom that touch people of all ages. Together with Gary's 25,000 hours of counseling experience and Barbara's gift of encouragement and biblical teaching, they are equipping thousands of families across the nation through their interactive daily radio program, conferences, and marriage and family resources.