I have a lot of of Protestant friends whom I love dearly. I am always encouraged and built up by their faith. One thing they often worry about however that I do not have to worry about as a Catholic is when my children will allow Jesus to come into their heart. You see, Jesus already lives in their heart through baptism. It is now up to me to cultivate that and help them fall in love with Him. Some ways I do this is through the rosary, reading scripture, playing worship music in our home and helping them to encounter Him everyday.
Through the sacrament of baptism, we are brought into the family of God and we are given the gift of the Holy Spirit. We baptize babies because the Jewish people never would have thought about leaving their children out of the Covenant. It makes sense that we wouldn't either with a new and even greater Covenant! We do not need to wait until our children have an understanding of who God is before He comes into their hearts. What a perfect picture of grace!
I also do not usually focus on getting my children to memorize different bible verses that deal with behavior. Instead every morning we say a decade of the rosary and for each mystery we talk about that aspect of Jesus' life and read the scripture that goes along with it. I want my children to love Jesus above anything else. When they hear the stories of Jesus' life hopefully it will help them fall in love with Him. His law will then be written on their heart and good behavior will naturally flow out of that relationship with Him.
The Lord has put it on my heart that my main goal before anything else each day needs to be to encounter Jesus and help my children encounter Him as well. The way I help my children to encounter Him every day is to have them pick a place in the house and seek Jesus for a few minutes. I tell them that if they are distracted to close their eyes and say His name over and over and then be still and listen. It is pretty amazing! They almost always hear from Him or see visions. I then have them write or draw pictures of what they see and hear in a prayer journal they keep.
Jesus said "Let the little children come to me" (Matthew 19:14). They are never too young and often grasp mysteries a lot better than most adults!