Age of 8 - Teach your children key principles by that age

We are told that it is critical for children to be taught the basic principles and ordinances of the gospel by the age of 8. Here's the verses discussing this from D.C. 68:

 25 And again, inasmuch as ^aparents have children in Zion, or in any of her ^bstakes which are organized, that ^cteach them not to understand the ^ddoctrine of repentance, faith in Christ the Son of the living God, and of baptism and the gift of the Holy Ghost by the laying on of the hands, when ^eeight years old, the ^fsin be upon the heads of the parents.

 26 For this shall be a law unto the ^ainhabitants of Zion, or in any of her stakes which are organized.

 27 And their children shall be ^abaptized for the ^bremission of their sins when ^ceight years old, and receive the laying on of the hands.

 28 And they shall also ^ateach their children to pray, and to walk uprightly before the Lord.

In a CES fireside talk, President Monson discussed this topic and mentioned the need to teach children while they are young. Here's his comments:

The Lord tells us in the Doctrine and Covenants that during the first eight years of our lives, power is not given unto Satan to tempt us as little children (see D&C 29:46–47). We had an eight-year head start on Lucifer.

This information was given by the Lord to the Prophet Joseph Smith back in 1830. In our own time Dr. Glenn Doman, a renowned scholar and scientist who has almost definitely never heard of the revelation quoted, has, through his research, come to the conclusion that “a newborn child is almost an exact duplicate of [a] computer, although superior to one in almost every way.

“What is placed in the child’s brain during the first eight years of life is probably there to stay. If you put misinformation into his brain during this period, it is extremely difficult to erase it.” He believed that the most receptive age in human life is that of two or three years old.3

You might ask, “Why is President Monson emphasizing this? Our first eight-year period of learning is long past.” But you, my brothers and sisters, are going to be parents one day, and you will want to emphasize the importance to your children and to your future generations of descendants of that first eight-year period.

Since having kids I've realized that they learn incredibly quickly. I want to make sure to help teach them the best that I can the critical things of life, such as the need to trust in God, believe in Him, keep his commandments, talk to Him, etc.