When I was my father's son, tender and the only one in the sight of my mother, he also taught me, and said to me: "Let your heart retain my words; keep my commands, and live." (Proverbs 4:3-4)
There will come a time in just about every child's life when that child will stop unconditionally trusting his or her parents. Therefore, while you have that window of trust, teach them as much as you possibly can. Mentor them, guide them and instruct them in the way that they are to go: as the Proverb says, "Train up a child in the way he should go, and when he is old he will not depart from it." If we instill into our children with great love and kindness: truth, integrity, how to work, share and serve, they will learn to cherish these godly characteristics. Even if they leave them for a season, they will by the grace of God return to them because they are instilled in them. As with all of us, repetition is a great teacher. Tell them over and over again. Remember, once isn't enough that's why there are four gospels.