Christian friends, if you have no conflicts in your marriage then something is wrong. Marriage is a “great mystery” — no relationship between human beings is greater or more important. It is spiritual partnership, sealed by covenant, for mutual sanctification, making us day-on-day more like Christ. Its end is to develop mature character. It is wonderful but hard: burning joy and strength, yet blood, sweat and tears, humbling defeats and exhausting victories.
A good marriage drives each of us to experience the gospel, the transforming love of God. You will see your spouse’s flaws to the bottom, see the other in complete nakedness. In the course of your life together, you will fail to do what you ought, want what you should, be who you should be. You will betray the other, will fail to love the other as you should.
But, with maturity, you will come to truly love your spouse more fully than you could possibly have imagined.
Source: The Meaning of Marriage by Tim Keller