God never allows pain without a purpose in the lives of His children. He never allows Satan, nor circumstances, nor any ill-intending person to afflict us unless He uses that affliction for our good. God never wastes pain. He always causes it to work together for our ultimate good, the good of conforming us more to the likeness of His Son (see Romans 8:28-29).
Sin is wrong, not because of what it does to me, or my spouse, or child, or neighbor, but because it is an act of rebellion against the infinitely holy and majestic God.
Truth is we must plant and we must water if we are to make progress with our children in holiness but only the Holy Spirit can change our children more and more into the likeness of Jesus. Our problem is we tend to depend upon our planting and watering rather than the Lord.
A son or daughter in any human family is either born to or adopted by the parents. By definition, a child can't be both. But with God we're both born of Him and adopted by Him.