now i know you must be kidding
God tested Abraham's faith. Abraham did as he said because he trusted God and knew God would not allow harm to come to his children, when God had previously said that a great nation would be his heirs through his son.
as for Job, if you didn't "get" it: Satan told God that Job only worshipped him because God gave him much material wealth and an easy life. God said no, he worships me because he believes in me and my goodness. so God took all he gave to Job away, and still Job worshipped him. God turned to Satan and basically said "see?". None of this would have happened if Satan had not brought up this vile accusation. moreso, the moral is material possession is nothing and happiness comes from within. Job had faith in God and with or without his stuff, he still believed.