The obedience of Abraham testified that he feared his God. Abraham loved his God, but in this love is also fear, not trembling fear, but a kind of great respect that God always wants the best for his children, Abraham, and his descendants. Abraham’s faith was important to God.
Abraham had given God the most precious he had on this earth, God wants to be loved with the best we have. Then God loved Abraham back, because Abraham gave his son Isaac, God is responding by giving His son for the descendants of Abraham, the Hebrews and then the whole world.
To kill Isaac wouldn’t have helped anybody, but sacrificing the Son of God would give the entire world a way to “life” on earth and a life forever with God in heaven. Jesus died for the sin in us to give us a new spirit to overcome the sin in our life.