How can they support shunning as scriptural?
Luke 15:11-32 (HCSB)
The Parable of the Lost Son
11 He also said: “A man had two sons. 12 The younger of them said to his father, ‘Father, give me the share of the estate I have coming to me.’ So he distributed the assetsto them. 13 Not many days later, the younger son gathered together all he had and traveled to a distant country, where he squandered his estate in foolish living. 14 After he had spent everything, a severe famine struck that country, and he had nothing. 15 Then he went to work forone of the citizens of that country, who sent him into his fields to feed pigs. 16 He longed to eat his fill from the carob podsthe pigs were eating, but no one would give him any. 17 When he came to his senses,he said, ‘How many of my father’s hired hands have more than enough food, and here I am dyingof hunger! 18 I’ll get up, go to my father, and say to him, Father, I have sinned against heaven and in your sight. 19 I’m no longer worthy to be called your son. Make me like one of your hired hands.’ 20 So he got up and went to his father. But while the son was still a long way off, his father saw him and was filled with compassion. He ran, threw his arms around his neck,and kissed him. 21 The son said to him, ‘Father, I have sinned against heaven and in your sight. I’m no longer worthy to be called your son.’
22 “But the father told his slaves, ‘Quick! Bring out the best robe and put it on him; put a ring on his fingerand sandals on his feet. 23 Then bring the fattened calf and slaughter it, and let’s celebrate with a feast, 24 because this son of mine was dead and is alive again; he was lost and is found!’ So they began to celebrate.
25 “Now his older son was in the field; as he came near the house, he heard music and dancing. 26 So he summoned one of the servants and asked what these things meant. 27 ‘Your brother is here,’ he told him, ‘and your father has slaughtered the fattened calf because he has him back safe and sound.’
28 “Then he became angry and didn’t want to go in. So his father came out and pleaded with him. 29 But he replied to his father, ‘Look, I have been slaving many years for you, and I have never disobeyed your orders, yet you never gave me a young goat so I could celebrate with my friends. 30 But when this son of yours came, who has devoured your assetswith prostitutes, you slaughtered the fattened calf for him.’
31 “ ‘Son,’he said to him, ‘you are always with me, and everything I have is yours. 32 But we had to celebrate and rejoice, because this brother of yours was dead and is alive again; he was lost and is found.’ ”