You cannot have somebody else atone for your sins. After the Israelites made a golden calf to worship, Moses rebuked them by having the calf destroyed. Moses then went to God and offered himself for the sins of Israel. God said “Those who have sinned against me are the ones I will blot out of my book (of life)…” and he did. Moses wasn’t able to atone for another’s sin (Exodus 32:31-35). You see, God holds us individually responsible without allowing anyone to pay for our sins. This concept of personal accountability is echoed throughout the Tanakh (Deuteronomy 6:1-25, Isaiah 3:10-11, Ezekiel 33:10). God and His prophets are insistent in saying that the others cannot pay for your sins (Deuteronomy 24:16, 2 Kings 14:6, Jeremiah 31:29-30). Ezekiel spends all of chapter 18 reinforcing this teaching. God also states that He is our only salvation (Exodus 15:2, Isaiah 12:2, 26:3-4, Psalm 27:1, 118:14) and not even Moses or a messiah can intercede in God’s role.
Yet we have the Christian messiah saying he paid for our sins like a ransom (Matthew 20:28, 1 Timothy 2:6, 1 Peter 2:24, 3:18). 1 John 2:2, 4:10 punches this home by stating that the Christian messiah atoned for our sins, which flies in the face of God’s original word, the Torah.
The closest thing that implies a human sacrifice was when God commanded Abraham to sacrifice his son Isaac (Genesis 22). However, at the beginning of this chapter it starts out by saying “…God tested Abraham…”. So this was a test of faith. We have conformation of this in verse 5 where Abraham says to the two boys that accompanied him and Isaac ““Stay here with the donkey. I and the boy will go there, worship and return to you.” Abraham confirms that after the worship (where he is supposed to sacrifice his son) he and Isaac will return together. Abraham had complete faith in God that it would somehow work out. The other take away from this is that, in the end, God did not support a human sacrifice.
Another point to ponder is Gehenna. This is the modern day Valley of the Son of Hinnom, which is just to the west of Jerusalem. This land is cursed because some of the kings of Judah sacrificed their children by fire (Jeremiah 7:31, 19:2-6, 32:35). This did not meet with God’s approval, no child sacrifice ever could and especially not His own.
To sum it up, God doesn’t change His mind when it comes to His commandments (Numbers 23:19, Isaiah 46:10-11, Malachi 3:6) and the Torah insists that we will not EVER use a human sacrifice (Genesis 22:10-12, Deuteronomy 18:10, Leviticus 18:21).