“Abraham stretched out his hand and took the knife to slay his son. But the angel of the LORD called to him from heaven and said, “Abraham, Abraham!” And he said, “Here I am.” He said, “Do not stretch out your hand against the lad, and do nothing to him; for now I know that you fear God, since you have not withheld your son, your only son, from Me.”” Gen. 22:10-12
Abraham is literally seconds away from killing his son when the angel of the LORD calls out and stops him. As Abraham carefully lowers the knife he is likely both perplexed and relieved; Relieved because his son shall live, and with him the promises of God concerning his descendants. Perplexed because his heart has surely been twisted in this ordeal, and in this last moment, untwisted, as the purpose of the test was revealed to Abraham. This was not just a test of faith; this test was mental, physical and emotional in nature. Every facet of Abraham was tested.
The heart of God is revealed to Abraham here as well. We must remember that Abraham grew up in Ur, and that his father, Terah, was an idolater (see Joshua 24:2). Abraham had likely at least heard of some of the other gods that demanded human sacrifice, if not experienced them more closely. Surely, as the one true God revealed Himself to Abraham, and Abraham started following Him in all obedience, Abraham was not even considering that God was like the other false gods in any way. But when God asked Abraham to offer up his only son, Abraham probably had many conflicting thoughts going through his head: He was weighing what this God has done for him; how this God has even told him of future events, such as Sodom and Gomorrah and the birth of his son Isaac, prophetically, how the angels saved Lot, the victory he had against the four kings with just 318 men, these were all good things. This God also asked Abraham to circumcise himself and his whole household, which was extremely painful for days, and aside from God’s promises, likely had no other obvious immediate benefit.
And now suddenly this God was asking for the offering of his only remaining son – the son that was promised and foretold, the son who was going to be the step to making Abraham into a great nation – and God was now asking Abraham to offer him up as if he were an animal, on the altar. Certainly Abraham had to make a choice at that point if he was going to keep following God, and did so. And so God shows His own heart to Abraham, that He was not like the other gods, He did not demand human sacrifice. Instead He relented, He showed His wonderful mercy. And this mercy is the heart of God.