What is the number one destroyer of marriage? Is it infidelity? Yes, infidelity wreaks havoc on marriages, but it is not number one. Is it hobbies? Yes, hobbies can behard on marrages, but they are secondary? Is it squabbles over money, or in-laws, or sex? Yes, all of these are responsible for much marital grief, but they are not number one.
I submit that the number one destroyer of marital harmony and intimacy is the small, insidious, seldom noticed sin of bitterness. You don't keep short accounts. Little wounds accumulate. They don't get healed. Eventually they become infected and kill your relationship. Twenty years into marriage you find yourself sleeping in separate beds.
Here is how it works. Your spouse does something to wound or hurt you, an unforgiven grievance from 12 years ago comes to mind. You combine them, and the pain is doubled. Now the resentment is amplified. "Forgiving is the hardest thing you will ever do," notes Andree Seu. "That's why most people don't do it. We talk about it, cheer for it, preach on it, and are sure we've practiced it. But mostly the illusion of having forgiven is that the passage of time dulls memory. The ruse will come to light with hair-trigger vengeance when fresh offense hurls in to empty out the gunnysack of half-digested grievances."
Only Christians have a really solid basis for forgiveness. It is the gospel. The gospel is why we forgive. The gospel reminds us that our sins were infinitely heinous in God's sight. Yet, despite this, God so longed to forgive that he sent his only begotten Son to be tortured to death in our place. Now that is mega-forgiveness. It is gross hypocrisy to accept this from Christ and not give it back to our spouse. Their offense against you, no matter how serious, is always finite, but your offense against God is always infinite.
Forgiveness is not a feeling. It is a repeted, heart-felt, act of the will. That is why Jesus, when Peter asked how many times he should forgive, responded 70x7 (Matt 18:22). Those who want happy marriages and increased intimacy do the same.