Should a married person have a close friend of the opposite sex?There is no place in the Bible that forbids men and women from being friends with each other. Friendships with the opposite sex are perfectly acceptable, even beneficial, within proper boundaries. But boundaries are necessary. Many people who have affairs would never have anticipated cheating on their spouses, but it still happened. Why? Because there were not proper boundaries in place. Married spouses should have mutually agreed upon boundaries that will protect their relationship and maintain their mutual trust.
When times in the marriage are good, it's easy to maintain external opposite sex friendships, because you are feeling more fulfilled by your spouse. However, when times get tough in a marriage, it can become a temptation to develop unhealthy emotional attachments, if not physical ones. Friendships require emotional investment, which is enriching and important; however, we have to be wise about with whom we form close emotional bonds. If a woman has a male best friend, not her spouse, she will most likely want to go to him as a confidant, advisor, and source of support when times are tough. The same is true for a man with a close female friend.
When a spouse is distant (physically or emotionally) and we have another friend of the opposite sex, it can be tempting to fill in the gaps of what is missing with our spouse with that person, which can lead to those classic "in love" feelings. As tough as it may be, it is a wiser choice to communicate directly with your spouse when you are having struggles rather than seeking comfort from another. Even an affair of the heart is still an affair. Consider the question, "Is this friend meeting a need for me that my spouse is a more appropriate person for?"
All that we do should be done for the glory of God (1 Corinthians 10:31), so we shouldn't put ourselves in contexts that could head in an unhealthy direction or be misconstrued in their intents. Whether your close friend is married or single, you also have to consider the space you may be occupying in their life and heart. Are you positioning yourself to create or meet needs in their life that you are unsuited to fulfill?
You can build a marriage on your foundation of faith in Christ, but that still won't make you immune to extra-marital temptation. The Bible instructs us to flee from lust and sexual temptation (2 Timothy 2:22). This instruction is not just for single people; it is for all people. Marriage doesn't cure lust and temptation. We all need to proactively flee from sexual sin, because that is a better option than trying to stand our ground and fight it (1 Corinthians 6:18). When unfaithfulness of any kind has occurred, it requires great time, consistency, and effort to rebuild the trust that was lost.
So, what's the purpose of this warning? It's a reminder for married men and women that they should do their best to avoid any potentially compromising situations or relationship dynamics with friends of the opposite sex. You may not agree with your spouse's boundary preferences, but you should come to a mutually agreed upon rule of behavior in your marriage. This could be by creating a "no solo time with friends of the opposite sex" boundary or a choice to only see certain friends in certain group settings. Develop healthy boundaries that work for both of you.
With marriage comes great joy and blessing, but also sacrifice. Things that may have been perfectly acceptable as a single person, become unacceptable as a married person. Some have described marriage as one big "yes" that comes with a lot of little "nos" attached. You are no longer your own (1 Corinthians 7:3–4).
Philippians 2:3–4 says, "Do nothing from selfish ambition or conceit, but in humility count others more significant than yourselves. Let each of you look not only to his own interests, but also to the interests of others." This is true of married couples and friendships alike—what is in the best interest of your spouse? What is in the best interest of your friend? These considerations are crucial for your marriage, and they are just as important for the friend in question.
What spiritual boundaries do we need in our lives?
What is a biblical definition of true friendship?
Does the Bible say anything about friends?
What does the Bible teach about marriage?
What is the purpose of marriage?
Truth about Marriage