I agree with the last paragraph completely. My oldest son, who was very close to his father, has struggled since the day his dad walked out on us.
My son at the age of 16, left home to live with his dad. This in many minds would constitute a "rebellious child".
Just this Christmas he came 'home' for a few hours and it was so good to see that my 'unconditional love, consistent discipline and ...authentic example of walking with Jesus' has not all been a waste. Right now he continues to live a life farther from God than I would choose for him, but he also has a knowledge and thirst for the unconditional love of his heavenly Father and earthly mother that I am absolutely positive will bring him into an amazingly close father/son relationship with his Eternal Father and isn't that the most important relationship of all.
For those of you out there like myself, I encourage you to continue living out the last paragraph of 'greatest gifts' and we will reap a harvest of our wayward children's souls for eternity.