A.W. Pink provided guidance to parents for raising godly children through instruction, example, discipline and prayer in A Word to Parents.  The key section of his message are captured in the quotes below.

God has entrusted to parents a most solemn and yet a most precious privilege. It is not too much to say that in their hands are deposited the hope and blessing—or else the curse and plague of the next generation….How prayerfully and carefully should they discharge their trust….The character of parents is to be a very large degree reproduced in their offspring…Most assuredly God will require an account of the children from the parents’ hands, for they are His, and only lent to their care and keeping.

1) Instruct your children in three ways.  First, instruct the consistently day after day.  Second, instruct them systematically about the doctrines of God starting early.  Third, use the question and answer format of a catechism to make the teaching more effective.  Pink’s comments are below:

Instruction should not be an occasional or sporadic thing, but one that is to have constant attention. The glorious character of God, the requirements of His holy law, the exceeding sinfulness of sin, the wondrous gift of His Son, and the fearful doom which is the certain portion of all who despise and reject Him, are to be brought repeatedly before the minds of the little ones. “They are too young to understand such things” is the devil’s argument to deter you from discharging your duty.

This instruction is to be given by reading to them the Holy Scriptures and expounding upon those things suitable for their age. This should be followed by catechizing them. A continued discourse to the young is not nearly so effective as when it is diversified by questions and answers. If they know they will be questioned on what you read, they will listen more closely—the formulating of answers teaches them to think for themselves. Such a method is also found to make the memory more retentive, for answering definite questions fixes more specific ideas in the mind. Observe how often Christ asked His disciples questions.

2) Be a good example to your children because you’ll otherwise invalidate everything you’re trying to each about God.  If you teach them that God wants them to pray, model praying when they’re watching and when they’re not.  If you read a Bible passage about forgiveness, be sure to ask their forgiveness when you sin against them.  Pink explains:

 It is at this point parents need to be most on their faces before God, daily seeking from Him that grace which they so severely need and which He alone can supply. What care they need to take lest they say or do anything before their children which would tend to corrupt their minds or be of evil consequence for them to follow! How they need to be constantly on their guard against anything which might render them contemptible in the eyes of those who should respect and revere them!  The parent is not only to instruct his children in the ways of holiness, but is himself to walk before them in those ways, and show by his practice and demeanor what a pleasant and profitable thing it is to be regulated by the divine law.

3) Enforce consistent, fair discipline with your family.

In Genesis 18:19, Abraham did more than offer good advice—he enforced law and order in his household. The rules he administered had for their design the keeping of the “way of the Lord”—that which was right in His sight…Rules should be simple, clear, reasonable and flexible like the Ten Commandments—a few great moral rules, instead of a multitude of petty restrictions…The parent is to punish a disobedient child not because he is angry, but because he is right—because God requires it, and the welfare of the child demands it.

4) Pray for your children daily.

The Throne of Grace is to be earnestly implored that your efforts to bring up your children for God may be crowned with success…A prayerful atmosphere should pervade the home and be breathed by all who share it.