In Luke, repentance is required (Luke5:32; Luke13:3, Luke13:5; Luke24:47), and the prodigal son narrative illustrates this instruction. The son, even if unaware, fulfills this requirement of repentance in turning to restoration (Luke15:17–20; Luke15:7, Luke15:10), expressing functional obedience while the father’s love preexists it; he is brought to willful submission to the father’s requirement for return and only thereby can he experience his father’s love. Likewise, belief in Jesus is functional obedience to God’s commanded requirement (1 John 3:23a), even if the new believer is initially unaware of the command. God is bringing us into willful obedience to Him whether or not we initially understand this.
The father loved his prodigal son, and there wasn't anything he could do to change his reckless behavior when he decided to use up his inheritance on a binge. He had to let his son go and hope/pray he would change his ways and return. "But when he came to himself, he said...I will arise and go to my father, and will say to him, 'Father, I have sinned against heaven and before you...'" (Luke 15: 17-18). Repentance - acknowledging our sin and turning to God for forgiveness and love. It's a true desire to change and submit to God in obedience. That's the only way God can start fixing us from the inside out.
This story hits home. I have a family member who has lived a reckless and selfish life for many years. No matter how we tried to help them, we were used and abused, and there was no desire for change. The person blew up on all of us earlier this year and blamed all of us for the alcoholism and destructiveness. They are off living on the other side of the state the last I heard, removed from the family and friends they once had. I've heard several say they can never forgive this person. But, I told them I will if they hit rock bottom, seek repentance, and ask for forgiveness. The love is there, but there would have to be "obedience" to the behaviors and actions we expect as a family. I'm sorry to say at this point that I don't have a lot of hope. The arrogance and will may beyond the point of no return. I pray I'm wrong and refuse to give up hope.
The prodigal son and the never ending mercy and love of God fuel that hope.