"But the father said to his servants, 'Quick! Bring the best robe and put it on him. Put a ring on his finger and sandals on his feet. Bring the fattened calf and kill it. Let's have a feast and celebrate. For this son of mine was dead and is alive again; he was lost and is found.' So they began to celebrate. (Luke 15:22-24 NIV)
This is how the father was...
= he gave love that was undeserving for his son
= he trusted his son
= he has sympathy toward his son
= he knows his son very well
= he was generous