There is perhaps nothing more heart wrenching for a Christian parent than to see their son or daughter living a life differently than how they were raised.
One biblical promise these parents can claim in prayer is—Train up a child in the way he should go: and when he is old, he will not depart from it (Proverbs 22:6).
But perhaps an historical example might be helpful as well—
Augustine was an undisciplined child, idle and truant despite frequent beatings. He loved sports and pranks and soon discovered a host of adolescent pleasures. … Augustine was also brilliant, and he soon moved to Carthage to further both his studies and his fun. Monica warned him against fornication, but ‘I ran headlong with blindness.’
At about 18 he found himself the father of a son. At the same time he joined a cult. Years passed, and Monica, praying ceaselessly, heard that Augustine was planning to leave Africa for Rome. She begged him not to go. When he refused, she determined to go with him. Using deception, he left her praying in a chapel and sailed without her; but she took a later boat and intercepted him. They traveled to Milan where she persuaded him to listen to the great Bishop Ambrose. The bishop’s razor-sharp sermons penetrated Augustine’s head, if not yet his heart. Monica continued praying, confiding her struggles to Ambrose. He told her not to worry: ‘It isn’t possible for the son of such prayers to be lost.’
One day as Augustine sat in a friend’s garden he heard a child singing, ‘Take up and read!’ He opened the Bible near him and read from Romans 13: ‘Don’t go to wild parties or get drunk or be vulgar or indecent.… Let the Lord Jesus Christ be as near to you as the clothes you wear.’ By the time he finished the sentence, he later said, he was converted. On the eve of Easter, April 24, 387, Augustine and his son Adeodatus were baptized by Ambrose as Monica watched. Her lifetime of prayer was answered, and a church father was born.
Years later as Augustine shared about his conversion in his book Confessions, he wrote out this prayer to God: “My mother, Your faithful servant, wept to You for me, shedding more tears for my spiritual death than others shed for the bodily death of a son. You heard her.”
So, Christian Mom and Dad, don’t EVER stop praying for your wayward child! God hears those prayers, and is moving on behalf of your child.