There is an interesting scripture that I think we underestimate as being more like wise counsel than a scripture.
Proverbs 22: 6 Train up a child in the way he should go: and when he is old, he will not depart from it.
After all, sometimes children of prophets turned away from the truth. But even though Lehi himself had some rebellious children, yet he personally testifies that this scripture is true in the Book of Mormon
2 Nephi 4:5 But behold, my sons and my daughters, I cannot go down to my grave save I should leave a blessing upon you; for behold, I know that if ye are brought up in the way ye should go ye will not depart from it.
So all of our imagined counterexamples to this are not correct.
Now I don't know what the Lord requires for a child to have been properly trained up in the way he should go. We will need the Holy Ghost with us to accomplish it. We will need to delve into the word of the Lord and put aside the philosophies of men. I don't think it is possible to train up a child in the way they should go without creating a family culture that requires perfect decency in our media, music, books, and website.
But I do know that if we train up a child in the way he should go, when he is old he will not depart from it.