Why does jesus use so many different parables to teach his disciples?

Parables are stories which illustrates one or more instructive principles, or lessons. They can be used to illustrate a wide or narrow understanding of a moral or religeous concept. One example is the Mustterd seed,

"The kingdom of heaven is like a grain of mustard seed which a man took and sowed in his field; 32 it is the smallest of all seeds, but when it has grown it is the greatest of shrubs and becomes a tree, so that the birds of the air come and make nests in its branches."

Thus good Christian practice begins with small acts and grows into something much larger.

PARABLES OF JESUS

Jesus told many parables (stories illustrating moral Truths). The most famous of these is perhaps the story of the Prodigal Son, which teaches us that though we may have rejected God and lived the life of a licentious wastrel, if we come home to him with a humble, contrite heart, God not only welcomes us with open arms but He rejoices. The Parable of the Sower teaches us that many people have heard the Word (Jesus) but for various reasons do not abide with Him. These reasons include succumbing to demonic influences; not making time to develop a true relationship with God through studying His Word and through prayer; allowing the concerns, worries, and the pursuit of wealth in this earthly life to be more important to us than Him.

Jesus showed His concern for all in the Parable of the Lost Sheep, which illustrates that even if 99 out of 100 sheep are safely abiding with a shepherd, he will diligently search for the one lost sheep until He finds it and brings it back into the fold. Jesus taught that we are not to treasure earthly things or to love money, particularly in the Parable of the Rich Fool, who stored up his wealth in bigger and bigger barns, took it easy, eating, drinking and merrymaking—not knowing his life would end that very night. Jesus encapsulated His entire teaching when He instructed that we must Love God with all our heart, soul, mind, and strength. And Love our neighbor as ourselves. Who is our neighbor? He is the person in your sphere whom you see is in need, as in the Parable of the Good Samaritan.