Continuously through history, humanity has enjoyed peaceful, prosperous times until they disobeyed God's commandments, especially the first commandment. As it was dictated to Moses when receiving the Ten Commandments in Deuteronomy 5:6-7, the first commandment says: "I am the LORD thy God, which brought thee out of the land of Egypt, from the house of bondage. Thou shalt have none other gods before me.".
Deliverers ranged from Joseph, Moses and Joshua to the judges and good kings. The first deliverer was Jacob's son, Joseph, who was sold by his jealous brothers into slavery in Egypt. You can read about Joseph in Genesis 37, 39-50, about Moses in Exodus, Numbers and Deuteronomy and about Joshua in the book of Joshua.
Unfortunately, several deliverers initially obeyed God, but relied more on their own efforts than the grace of God. God raised up Moses to lead the captive Israelites on the Exodus out of Egypt. Moses was denied the privilege of living in the promised land of Canaan for his disobedience. Several kings also fell short of total obedience to God including Solomon who was entrusted to building the temple that his father, David, was tasked with initially. Because Solomon compromised his values by choosing to allow worship of false gods, the Israelites (descendants of Jacob) were punished by slavery in Mesopotamia after God allowed the Assyrians and Babylonians to overcome them. Cyrus the Persian could be considered another deliverer since he allowed the Israelites to return to their homeland from Mesopotamia.
Hebrews 11, known as the faith Hall of Fame, lists those considered righteous. Even unlikely characters such as Rahab the prostitute played roles in setting the stage for mankind's savior. God used and still uses everyday, ordinary people to do extraordinary things.
The Old Testament segways to the Messiah of mankind, Jesus Christ. As the Son of God, He set the new standard where Moses and others fell short. Jesus' purpose was to make certain we recognized God's unfailing love for us.
Our response to God's mercy should be to live a life of gratitude where others can see God's love reflected in our attitudes and actions.