Why are so many children that are being raised in Christian homes leaving the faith when they grow up?
Josh McDowell gives statistics on this and it doesn't paint a pretty picture. Michael Pearl wrote a series on this called "Jumping Ship" and has some very good explanations why this is happening. I am just going to summarize what I recall the reasons he explained were for this happening so often.
If children are raised in an environment where mom and dad love each other, live out their faith, and are joyful, the chances of the children not jumping ship are high. If, on the other hand, they argue a lot, only go to church on Sundays and then don't exhibit any fruit in their lives, make up rules that don't match with Scripture, and always murmur and complain, there is a good chance their children will jump ship.
We need to make loving Jesus look like the most wonderful thing in the world ~
We need to be joyful and happy.
We need to be loving and kind to everyone we meet, especially to our family.
We need to be consistent in our discipline and train them in the way they should go.
We also need to protect them and give them boundaries.
They want and need boundaries. We were strict with our children, but they grew up feeling loved and protected. Read Proverbs to them a lot so they will grow up "in the nurture and admonition of the Lord." Yes, it takes hard work but the benefit to having children that "walk in truth" is immeasurable.