Marriage is an ancient practice, but there are numerous misconceptions surrounding its nature and purpose. Author and pastor Timothy Keller seeks to clarify what marriage is really about.

"Submit to one another out of reverence for Christ." — Ephesians 5:21

For both husband and wife, the most important (and most challenging) object of marriage is to live for the other rather than oneself. Opportunities for a husband and wife to serve each other come up constantly throughout the day. We can either joyfully serve the other, begrudgingly serve the other, or insist on getting our own way. The first option is by far the hardest to put into practice, but it is the only way both parties will enjoy happiness and fulfillment in marriage.

In a letter to the Corinthians, Paul demonstrates that love is the opposite of "self-seeking" or self-serving. We respond to self-centeredness in kind because self-centeredness in its essence prevents you from seeing its work within you and keeps you appalled by and sensitive to the self-centeredness of others. It has a corrosive effect on the marriage, eating away at what is good until it there’s nothing left but despair and bitterness.

If the goal is to serve the other—rather than to be happy—you will both end up being happiest. Both sides must have the same selfless goal.

Most problems in marriage are rooted in one or the other being selfish, seeking to have their needs met over and above the needs of the other. And we always consider the other partner's selfishness as more problematic than our own. But when we do that, we put the emphasis on their need to change. When both sides do this, resentment builds and distance is created. Both sides will feel hurt and frustration at things the other partner does or doesn't do for them, but they'll resign themselves to just live with this new reality, and the marriage might survive, but it will never thrive. They will be "settling" for a marriage that doesn't fully satisfy.

The answer is to treat our own self-centeredness—not our spouse's—as the primary problem. No excuses or justifications. Take ownership of your own behavior. When both sides do this, marriage thrives and a deeper happiness and satisfaction are enjoyed on both sides. Think of yourself less, and of your spouse more, and the rest will fall into place. Your partner's joy should not be robbed by the crushing obligation to always meet your needs. Rather, they should be liberated to joyfully and willingly meet your needs just because you're their spouse, and you've self-sacrificially taken the initiative to meet theirs. This is biblical love in marriage.

Biblical love is sacrificial commitment to the good of another. You can measure your love for someone by how much you’re willing to give up for them. How much are you willing to invest in them?

Love is not just an emotional feeling, but action and duty. You can’t expect to both be in the mood for sex all the time. That’s unrealistic. But a willingness to please the other when he or she is in the mood can produce the right mood in you on the spot. When it is a privilege to pleasure your spouse and bring him or her joy—rather than a mechanical, heartless obligation—the act can change your mood.

C.S. Lewis said that if you act like you love someone, you will begin to actually love him. The same principle can work in the bedroom. Act like you desire your spouse—behave as if you were in the mood—and the mood will come. What starts as a performance turns into genuine pleasure.

The good of the relationship takes precedence over the immediate needs of the individual. This is because marriage is a covenant not just with each other, but with God. Your duty and commitment to your spouse is akin to that of your duty to your children. You do not cut ties when parenting becomes difficult—the commitment is not contingent on how you feel. It isn’t merely emotional. Same with marriage. It’s much deeper than that. Sometimes you aren’t loved the way you want to be, but if you return the neglect with neglect of your own, the marriage will spiral into decay and die. Two-thirds of unhappy marriages become happy again within five years if they stay together instead of divorcing. The duty of marriage is to keep acting in love, even in the moments when you don’t feel like it. Doing so may be hard, but it will revive your marriage like nothing else can.

While it's important to understand what marriage is, it's equally important to understand what marriage is for. Marriage is the most profound relationship possible. It is the union of two people as best friends and lovers. Rather than being alone, a married person has a built-in partner for life, someone who will be there every step of the way, supporting and loving you as you are molded and shaped into the person God wants you to become. The importance of friendship and companionship in marriage cannot be overstated. If sexual attraction or financial standing are what bind you together, your relationship will always be vulnerable; it is on a weak foundation. Friendship must underlie everything else as the bedrock for the relationship.

The marriage relationship is the most important relationship, even more so than the parent-child relationship. God did not put a parent and a child in the garden of Eden—rather, he put a husband and a wife together. As the most important relationship you'll ever have, it must get more investment and energy from you than anything else. Nothing in your life is more important or deserving of your attention and care. Of course, if your marriage is your focus, you'll be an even better parent as a result. Focus on your spouse, and the relationship with your children will thrive. Focus on the children to the neglect of your spouse, and your family will crumble.

When a man complains that he feels secondary to the kids, the schedule, the dishes, the chores, the busyness of life, the marriage is in danger. His wife has failed to prioritize him. When a woman complains that she feels secondary to the kids, the career, the clients, and so on, the marriage is in danger. Her husband has failed to prioritize her. Counseling is often needed in these scenarios to get the couple focused on what's most important: each other.

We are all flawed and imperfect. While you may be somewhat blind to each other's flaws when you first meet and fall in love, you cannot stay blind to them once married. Think of a bridge that has some cracks and fissures in it, then imagine a heavy truck driving across it. The truck's weight causes the cracks to widen and deepen. It does not cause the cracks in the first place; rather, it exposes them and makes them more obvious. In the same way, marriage applies pressure on individuals in ways that cause their pre-existing flaws and weaknesses to be exposed. We may blame our spouse for making us behave a certain way, but the spouse is no more to blame than the truck.

In truth, the fact that our spouses expose our character flaws is one of the benefits of marriage. It allows us to identify the areas where we need to do the most work on ourselves. Thus we can see that marriage has the power of truth; it has the power to make us confront our shortcomings and character flaws, and grow into better people as we deal with them. The healthiest marriages are the ones where both spouses welcome the truth from each other. They welcome their own exposure and the gentle criticisms of their lovers so they can grow into better life partners over time. One of the ways of loving your spouse is to speak truth to them)—not to tear them down, but to help them grow.

Don't blame your spouse for your unhappiness. Don't withdraw when you encounter their flaws. Don't downgrade your expectations. Don't settle for just "getting along." Don't, upon becoming frustrated with your partner's shortcomings, seek another partner who doesn't have the same flaws. Rather, speak the truth to each other in love, and be willing to act on what you hear. If you already have the desire to work on your problems, rather than run away from them, then you're well on your way to a healthy, happy marriage.

Love comes in different currencies. Give love in the currency that your spouse values. If your spouse values acts of service, giving her flowers will be nice, but it won't be as powerful and effective as helping with the household chores. If you're out of sync with each other—that is, speaking different love languages or using different currencies—you'll find yourself feeling depleted. You'll be giving of yourself in ways that aren't appreciated, and your own emotional and physical needs won't be satisfied. It is also important to recognize and appreciate the love being offered, even if it isn't coming through in your preferred language. Your spouse is trying, in such cases, even if they aren't perfectly in tune with you.

Never abuse the primary love language of your spouse. Never withhold it to hurt them, or hold it over their head as a manipulative tool. For example, a man who deeply values respect will be wounded to the core if his wife mocks him publicly with intent to hurt him.

Telling the truth to your spouse is important, but equally important is the need to forgive and exercise grace when your spouse sins or fails you in some way. Just as Christ forgave us, we must be willing to forgive each other without holding onto resentment.

Terms like “headship” and “submission” are controversial until you understand them in their proper context, with Christ as the model. If God himself could become a servant for others without damaging his dignity, so can we. A wife’s submission to her husband is not degrading or demeaning; it is God’s design. There is nothing greater than aligning one’s life and purpose with God’s original intent and design for you. Christ showed greatness, not weakness, when he came to submit and serve. The same can be said of the submissive wife.

Men are not exempt from the challenge of submission. They are called to be servant-leaders—to love their wives self-sacrificially, as Christ loved the church. The world's understanding of leadership looks down on those who are submissive, but Christ provides the proper model for what true leadership is meant to look like. In biblical marriage, wives submit to their husbands, and husbands love their wives self-sacrificially, even to the point of death. While the roles differ, neither is greater than the other, and neither spouse should put their own interests first. Conformity to God's design confounds the world, but it is the way things were meant to be, and it is the best thing for us.

What if you aren't on the same page? Ultimately, you can only control your own behavior. You can't make your spouse love and serve you the way you love and serve them. You can only do your part, and nothing is more likely than that to motivate your spouse to reciprocate.

While many think the Bible has a low view of sex—treating it as dirty or degrading—nothing could be further from the truth. The Bible refutes that misconception at every turn, offering a positive view of sex and sexuality. It also limits sexual activity to the confines of marriage between one man and one woman.

Marriage is the union of a man and woman in every way—legally, financially, socially, emotionally, and physically. Sex deepens and maintains that union. It is the most powerful way to give yourself to another, to communicate to them that you are theirs. It isn't just about personal satisfaction or gratification; it's about self-giving, and reinforcing the marriage covenant. It unites two people "as one flesh," and that is why it must be confined to marriage. If you use a prostitute for your own pleasure, you're divorcing sex from its purpose as a uniting feature of marriage commitment. Like chewing food without swallowing, sex outside marriage robs you of the actual benefits (and purpose) of the act.

Married couples are instructed to enjoy sex on a regular basis. Paul reminds married couples that their bodies are not their own; in the marriage union, the husband's body belongs to his wife, and vice versa. Each spouse has an obligation—one that should be joyfully met—to sexually satisfy the other according to their needs. Denying each other is prohibited, except by mutual consent.

Your primary purpose in sex should not be your own gratification, but that of your spouse. Nothing should bring you greater pleasure than pleasuring your spouse. Commit yourself to being aroused by producing arousal in your spouse and your sex life will flourish. This is an important principle, especially for the spouse with a lower sex drive. If your purpose in sex is to give pleasure, rather than receive it, you'll give it joyfully as a gift to your spouse who wants and needs it more than you. With the right heart and mentality in place, their satisfaction will bring you satisfaction.

If you think of your marriage as an engine, sex is the oil that keeps it running smoothly. A healthy, joyful sex life keeps the engine lubricated, reducing friction. Never stop working on improving your sex life.

Sex is glorious. God meant for it to be rapturous for us, but he also intended it as a foreshadowing of the glorious union we'll one day share with Christ.