It is very difficult for the words spoken by Buddha from the far bank of Enlightenment to reach the people still struggling in the world of delusion; therefore Buddha returns to this world Himself and uses His method of salvation.
"Now I will tell you a parable," Buddha said. "Once there lived a waelthy man whose house caught on fire. The man was away from home and when he came back, he found that his children were so absorbed in play, had not noticed the fire and were still inside the house. The father screamed, 'Get out, children! Come out of the house! Hurry!' But the children did not heed him.
"The anxious father shouted again, 'Children, I have some wonderful toys here; come out of the house and get them!' Heeding his cry this time, the children ran out of the burning house."
This world is a burning house. The people, unaware that the house is on fire, are in danger of being burned to death so Buddha in compassion devises ways of saving them.