God speaking in Exodus 13 permits redemption sacrifices. It says that instead of murdering your firstborn son as a sacrifice to God you can use a lamb etc. The chapter ends by saying how sacred such murder is for God killed the firstborn boys of Egypt. Yet Christians say such sacrifices of animals stand for the coming death of Jesus offered to God for cleansing sinners of sin! But animal sacrifice was child-sacrifice by proxy!
Earlier, in Genesis 22, human sacrifice is declared not to be intrinsically immoral in the sight of God. It paved the way for rubbish like the above.
God tells Abraham to take his son, Isaac, up Mount Moriah and offer him up as a burnt offering. A burnt offering is killed first and then cooked and often eaten in a communion rite. Abraham obeyed God and when he had drawn out his knife to kill the boy, God’s messenger came to tell him not to do it for God had not been serious. So God had lied in telling Abraham that he wanted Abraham to kill the boy. But at the same time his command shows that he approves of human sacrifice for Genesis regards God as good and therefore unable to command immorality. Also Abraham was praised and blessed by God for stirring up the desire to brutally slay his own child in the name of religion. God told Abraham that he would start a great nation through Isaac. This is used as an excuse for saying, "Abraham knew God would stop him," or, "He surmised that God would raise the boy back to life" [A lie that comes from Hebrews 11:19]. The thought that God might preserve his sperm never occurred to him then! None of that changes the fact that Abraham and God were condoning commands to murder and those commands being taken seriously. Abraham was even going as far as to condone obeying a command to kill a boy that did not fit the promise that the boy would father a great nation. The excuses are more disgusting than the story. The story does not use them. Jesus supposedly expected to become a human sacrifice for sin which was probably why he honoured Abraham so much. He even told a parable of the rich man and a poor man with Abraham in Paradise saying that those who ignore the law and the prophets would not be converted even if a man should rise from the dead to warn them.
The story says Abraham lied to people so that he could take his son up Moriah to sacrifice him to God. Not only have we a story praising God for commanding murder and a man praised for obeying God, but it is a man who was prone to lying. If I were a liar, I would not like to be sure that revelations from God really were from God especially ones that command me to kill. It is an insult to be expected to trust the account which supposedly came from Abraham.