Why is abraham such an important figure in early jewish history?

Abraham is an important figure in Jewish history because God promised him that his descendants would multiply like grains of the sand and stars in the sky. He was a father of many nations. His descendants later became the people of Israel. He also is known because he trusted God with everything in his heart, and his belief that God would meet his needs is an example for many Jews to follow. It teaches them to trust God and his promises and plan for you.