Read Genesis 22:12-19      "Do not lay a hand on the boy," he said. "Do not do anything to him. Now I know that you fear God, because you have not withheld from me your son, your only son."  Abraham looked up and there in a thicket he saw a ram caught by its horns. He went over and took the ram and sacrificed it as a burnt offering instead of his son.  So Abraham called that place The Lord Will Provide. And to this day it is said, "On the mountain of the Lord it will be provided."  The angel of the Lord called to Abraham from heaven a second time and said, "I swear by myself, declares the Lord, that because you have done this and have not withheld your son, your only son, I will surely bless you and make your descendants as numerous as the stars in the sky and as the sand on the seashore. Your descendants will take possession of the cities of their enemies, and through your offspring all nations on earth will be blessed, because you have obeyed me."  Then Abraham returned to his servants, and they set off together for Beersheba. And Abraham stayed in Beersheba. 

Abraham passed the ultimate test. God asked him to give up what was most precious in life to him, and he gave his son to God.  And then God did, indeed, provide a ram, conveniently stuck in a thicket, which Abraham sacrificed instead of his son.  God promised him blessings and honor because of his obedience in this test, and repeated His promise that all nations would be blessed through him; the Messiah would be born of Abraham's lineage.  One day God's only Son would be the Lamb placed on the wood and pierced with a soldier's cruel spear.  It wouldn't be a test; it would be the real deal, and God would turn His holy eyes away from the sin of the world Jesus took on Himself on an old rugged cross.  No one would call out to intervene and save Him. He would give Himself willingly--the Sacrificial Lamb for the sin of the world.

This is what the Bible says about the new covenant God makes with us through His Son, Jesus Christ:

Read Genesis 22:9-11     When they reached the place God had told him about, Abraham built an altar there and arranged the wood on it. He bound his son Isaac and laid him on the altar, on top of the wood.  Then he reached out his hand and took the knife to slay his son.  But the angel of the Lord called out to him from heaven, "Abraham! Abraham!" "Here I am," he replied.