Those who trust in God will occassionally be tested by him. In the case of Abraham, the test was very tough! To be asked to sacrifice his only son would’ve been a big test of Abraham’s faith. For Abraham knew God would not contradict himself, yet this appeared to be a contradiction – the sacrifice of his son.
Regardless, Abraham prepared for the sacrifice, collecting wood, saddling up the donkey and looking to the point where it would happen.
Despite the apparent contradiction, Abraham still trusted God to provide an alternative. This can be seen in the account, with Abraham telling his servants both he and his son would return, and also telling Isaac that God would provide a lamb.
Right up until the final moment, Abraham carried out all the actions necessary, and then God provided the substitute. Not only did this result in Abraham being blessed, but through this all nations would be blessed.
It would be through the line of Abraham, that the ultimate sacrificial substitute would come. For Jesus Christ would one day be born to be sacrificed on a cross to take on the sins of those who believed in him.
Just as Abraham was willing to sacrifice his only son, we should be prepared to sacrifice whatever is most important to us. If God the Son gave up his life that I might live, how much should I be willing to give up?
I have been crucified with Christ and I no longer live, but Christ lives in me. The life I live in the body, I live by faith in the Son of God, who loved me and gave himself for me. Ga 2:20