I think the answer is that we have been blessed by God without some of the problems some families face. But, I also think we have done some things that have helped us maintain a strong marriage.
First, we both were believers when we got married. Neither of us were super strong in our faith, but both of us had the desire to grow. This is important because the Bible says:
Be ye not unequally yoked together with unbelievers: for what fellowship hath righteousness with unrighteousness? and what communion hath light with darkness? And what concord hath Christ with Belial? or what part hath he that believeth with an infidel? And what agreement hath the temple of God with idols? for ye are the temple of the living God; as God hath said, I will dwell in them, and walk in them; and I will be their God, and they shall be my people. Wherefore come out from among them, and be ye separate, saith the Lord, and touch not the unclean thing; and I will receive you. And will be a Father unto you, and ye shall be my sons and daughters, saith the Lord Almighty.
2 Corinthians 6:14-18
Second, we have learned to follow the roles God laid out. To an unbeliever, being a submissive wife might seem demeaning or "un-feminist." But, as a believer, I have found this to be very rewarding and not in the least bit demeaning. It first takes learning to submit to God. This I learned the best when I was pregnant with AJU5. Her pregnancy wasn't our plan at the time. I wanted to work full time longer (i had only been full time for a year). We were looking for a new house. We had plans. But, God had a better plan. I learned to submit to that over time. It took until Week 18 of that pregnancy to start submitting really, but I did. Putting our future in His hands made everything so much simpler. There had been times in the past we have put things in His hands - my husband's job during his senior year of college, finding our first home, etc. But, this one was the first time that I really had to submit and I couldn't do anything else. My husband had to learn to love me as Christ loves the church as well. To a woman, this seems easy. As women, it is easy to love. But, for men it is a lot harder. He has learned to nurture me. He has learned to support me when I need it. He has learned when to back off for a few minutes and let me settle down. Are either of us perfect in this? No. There are times I don't want to submit to him and rebel. There are times he isn't very loving. But, most of the time when we start to get close to a fight, I think both of us remember these verses:
Wives, submit yourselves unto your own husbands, as unto the Lord. For the husband is the head of the wife, even as Christ is the head of the church: and he is the saviour of the body. Therefore as the church is subject unto Christ, so let the wives be to their own husbands in every thing. Husbands, love your wives, even as Christ also loved the church, and gave himself for it; That he might sanctify and cleanse it with the washing of water by the word, That he might present it to himself a glorious church, not having spot, or wrinkle, or any such thing; but that it should be holy and without blemish. So ought men to love their wives as their own bodies. He that loveth his wife loveth himself. For no man ever yet hated his own flesh; but nourisheth and cherisheth it, even as the Lord the church: For we are members of his body, of his flesh, and of his bones. For this cause shall a man leave his father and mother, and shall be joined unto his wife, and they two shall be one flesh. This is a great mystery: but I speak concerning Christ and the church. Nevertheless let every one of you in particular so love his wife even as himself; and the wife see that she reverence her husband.
Finally, we spend time together. We are home 6 nights a week. The night we aren't together we are spending time studying and learning about God. We probably should go to evening services at church more (there are two other nights during the week we could go), but since the end of AJU7's pregnancy it hasn't been easy. There isn't a kids' program those nights, so we are always distracted by them. And it runs right up to if not past their current bed time (7:30). But, those are excuses... Back to spending time together. We aren't going different directions every night of the week. We spend time as a family and as a couple, even though we don't go on dates. Most nights after the kids are in bed we do something together (normally watching TV for about 45 minutes). But, we also have played games, etc. I think this helps our marriage a lot because we have a chance to grow together both as a family and as a couple.
So, there it is. I count it a blessing we haven't had any big fights in about 5 years. We have had small ones, but we used to have a lot more fights for sure...