There is no section in the Bible titled, "How to Have a Godly Marriage and How to Raise Kids."
Surely, the Bible has things to say about those topics. But they are scattered against a background of general Judeo-Christian belief and world-view. The Bible itself is a story of God's dealings with man. We treat our spouses properly, and raise our children properly, as an outpouring of what we already have in Him. Our dealings in this life in whatever positions we find ourselves in are informed and guided by our understanding of the Lord Jesus Christ. There is no right or wrong for the Christian outside of the mind of Christ, which operates in love according to His goodness and mercy to all of man's predicament and suffering.
This is why I do not like applicational teaching. The silver, gold, and precious stones of I Cor 3 are not workbooks on how to do some-thing or how to be the best some-one in a particular relationship or area of life. They are the teachings of the word of God as they inform us of Christ's mind towards our lives and the world. We go to Him, we learn of Him, we stand in awe of Him, and we come away automatically equipped in the Spirit for whatever calling God places in our lives.
Applicational teaching, then, not only refocuses our view of Scripture from a book detailing the love, grace, and holiness of God to a how-to manual, but in doing so it trends toward legalism. This is what we would expect when it is suggested that our lives in a certain area be lived according to particular guidelines not explicitly stated in Scripture.
"'Come to me, all you that are weary and are carrying heavy burdens, and I will give you rest. Take my yoke upon you, and learn from me; for I am gentle and humble in heart, and you will find rest for your souls. For my yoke is easy, and my burden is light.'"
-Matthew 11:28-30 NRSV