An agnostic asked me why did a loving God ask Abraham to kill his own son? I told him it was a test from God. Did answer him correctly? I did not say anymore
God hates human sacrifice.
Let no one be found among you who sacrifices their son or daughter in the fire, who practices divination or sorcery, interprets omens, engages in witchcraft. (Deuteronomy 18:10, NIV)
God was only testing Abraham's faith and obedience.
1 Some time later God tested Abraham. He said to him, “Abraham!” “Here I am,” he replied. 2 Then God said, “Take your son, your only son, whom you love—Isaac—and go to the region of Moriah. Sacrifice him there as a burnt offering on a mountain I will show you.”
12 “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.”
God never really wanted Abraham to sacrifice his son. God has no need of it. Our God doesn't need to eat food or need to sleep. God doesn't even need your money. God wants your faith, obedience and your love.
Love the LORD your God with all your heart and with all your soul and with all your strength. (Deuteronomy 6:5, NIV)
I have thought often about this one, especially as my own father's first male child died after half an hour of life. The only conclusion I have ever arrived at is that God had a message for Abraham. Your son is mine; but I want him alive. There were religions around at the time in which babies were sacrificed. God was instructing Abraham. In short, I connect this with Leviticus 18:21; "And thou shalt not let any of thy seed pass through the fire to Moloch."