I believe that the idea of Jesus Christ dying for man’s sin has its origin in the ancient concept of offering human sacrifices to a deity. We know human sacrifice was common in ancient times.
Human sacrifice is the act of killing human beings as part of a religious ritual (ritual killing). Its typology closely parallels the various practices of ritual slaughter of animals (animal sacrifice) and of religious sacrifice in general. Human sacrifice has been practiced in various cultures throughout history. Victims were typically ritually killed in a manner that was supposed to please or appease gods, spirits or the deceased, for example as a propitiatory offering, or as a retainer sacrifice when the King's servants are killed in order for them to continue to serve their master in the next life.
Human sacrifice has been practiced on a number of different occasions and in many different cultures. The various rationales behind human sacrifice are the same that motivate religious sacrifice in general. Human sacrifice is intended to bring good fortune and to pacify the gods, for example in the context of the dedication of a completed building like a temple or bridge. There is a Chinese legend that there are thousands of people entombed in the Great Wall of China. In ancient Japan, legends talk about Hitobashira ("human pillar"), in which maidens were buried alive at the base or near some constructions as a prayer to ensure the buildings against disasters or enemy attacks. For the re-consecration of Great Pyramid of Tenochtitlan in 1487, the Aztecs reported that they killed about 80,400 prisoners over the course of four days. According to Ross Hassig, author of Aztec Warfare, "between 10,000 and 80,400 persons" were sacrificed in the ceremony. (“Human Sacrifice,” in Wikipedia)
Even conservative Bible scholars acknowledge the prominence of human sacrifices in the ancient world. For example the article “Sacrifice, Human”, in the International Standard Bible Encyclopedia(ed. James Orr) states:
As an expression of religious devotion, human sacrifice has been widespread at certain stages of the race's development. The tribes of Western Asia were deeply affected by the practice, probably prior to the settlement of the Hebrews in Palestine, and it continued at least down to the 5th century BC. At times of great calamity, anxiety and danger, parents sacrificed their children as the greatest and most costly offering which they could make to propitiate the anger of the gods and thus secure their favor and help. There is no intimation in the Bible that enemies or captives were sacrificed; only the offering of children by their parents is mentioned. The belief that this offering possessed supreme value is seen in Micah 6:6 ff., where the sacrifice of the firstborn is the climax of a series of offerings which, in a rising scale of values, are suggested as a means of propitiating the angry Yahweh. A striking example of the rite as actually practiced is seen in 2 Ki 3:27, where Mesha the king of Moab (made famous by the Moabite Stone), under the stress of a terrible siege, offered his eldest son, the heir-apparent to the throne, as a burnt offering upon the wall of Kir-hareseth. As a matter of fact this horrid act seems to have had the effect of driving off the allies.
Human sacrifice was ordinarily resorted to, no doubt, only in times of great distress, but it seems to have been practiced among the old Canaanitish tribes with some frequency (Dt 12:31). The Israelites are said to have borrowed it from their Canaanite neighbors (2 Ki 16:3; 2 Ch 28:3), and as a matter of fact human sacrifices were never offered to Yahweh, but only to various gods of the land. The god who was most frequently worshipped in this way was Moloch or Molech, the god of the Ammonites (2 Ki 23:10; Lev 18:21; 20:2), but from Jeremiah we learn that the Phoenician god Baal was, at least in the later period of the history, also associated with Molech in receiving this worship (Jer 19:5; 31:35).
Dr. David R. Dilling, a graduate of Wheaton College and Grace Theological Seminary, writes: In Mesopotamia, for example, we have the positive evidence of a published Babylonian cylinder seal which unmistakably portrays the actual execution of a human sacrifice. A.H. Sayce, British Assyriologist of a generation ago, has called attention to an Akkadian poem of pre-Semitic times with its later Assyrian translation concerning the sacrifice of a firstborn son. It says distinctly, "His offspring for his life he gave." Biblical evidence that human sacrifice was known in Mesopotamia in later times is found in II Ki. 17:31, ". . .And the Sepharvites burnt their children in the fire to Adrammelech and Anammelech, the gods of Sepharvaim."(The Atonement and Human Sacrifice, Grace Theological Journal 12.2 [Spring, 1971]).
We know that some Jews also practiced human sacrifice, albeit to a foreign deity, Molech. King Ahaz is said to have “made his son pass through the fire”, a clear reference to human sacrifice (2 Kin. 17:17; ). King Manasseh, likewise, is said to have made his son “pass through the fire” (2 Kin. 21:6). “Pass through the fire” in the King James Version is rendered “sacrifice in the fire” in the New International Version and “give to be burned as a sacrifice” in the New Living Translation.
The International Standard Bible Encyclopedia in the article on “Molech,“ says regarding the phrase “pass through the fire”:
When we come to consider the nature of this worship it is remarkable how few details are given regarding it in Scripture. The place where it was practiced from the days of Ahaz and Manasseh was the Valley of Hinnom where Topheth stood, a huge altar-pyre for the burning of the sacrificial victims. There is no evidence connecting the worship with the temple in Jerusalem. Ezekiel's vision of sun-worshippers in the temple is purely ideal (Ezek 8). A priesthood is spoken of as attached to the services (Jer 49:3; compare Zeph 1:4,5). The victims offered to the divinity were not burnt alive, but were killed as sacrifices, and then presented as burnt offerings. "To pass through the fire" has been taken to mean a lustration or purification of the child by fire, not involving death. But the prophets clearly speak of slaughter and sacrifice, and of high places built to burn the children in the fire as burnt offerings (Jer 19:5; Ezek 16:20,21).
So it is clear that some Jews in the Old Testament period practiced human sacrifice (Jer. 32:35; Eze. 16:21, 20:26, 20:31, 23:37).
While Yahweh was displeased with these human sacrifices and forbade them (Lev. 18:21; Dt. 18:10), it seems that his main problem was that they were offered up to a foreign god. As the evangelical theologian, David Dilling says:
1) The legal prohibitions, as well as the prophetic polemics, are uniformly related to heathen deities. In the passages cited, human sacrifice occurs almost incidentally amid lists of abominations rendered in connection with idolatrous worship. (2) The greater offense is not the sacrifice, but the idolatry involved in offering such a sacrifice to a god other than Yahweh. The first commandment is not, "Thou shalt not offer human sacrifices, "but, "Thou shalt have no other gods before me." (3) The Bible contains no prohibitions of human sacrifice to Yahweh. The only possible exception to this principle is the legislation regarding the redemption of the first-born sons in Ex. 13:1-16. This passage, however, does not condemn human sacrifice. On the contrary, it proves that Yahweh had a very definite claim on all the first-born of Israel, whether man or beast.( p. 25).
One can also argue that Yahweh’s command to Abraham to offer up Isaac is evidence that human sacrifice, in principle at least, was an acceptable idea in OT times. God’s command to Abraham in Genesis 22 has been unsettling to many a Christian commentator or theologian. Many conservatives have argued that it was never Yahweh’s intention for Abraham to go through with the sacrifice but that he was simply testing Abraham’s faith. Dilling, however, takes great issue with this notion. He writes: The most frequent objection raised against the Biblical presentation of Yahweh and His relationship to sacrifice is that sacrifice, whether of human beings or of beasts, is an element of primitive religion, and that Yahweh really desires not sacrifice at all but obedience. . . . This view, carried to its logical conclusion, would eliminate the necessity of the sacrificial death of Christ. This in turn eliminates the atonement and thereby abnegates the whole Christian gospel.(pp. 26-27).
I think Dilling is right. If one argues that human sacrifice, per se, is unacceptable to God, then one must also maintain that the sacrificial death of Jesus Christ, was unacceptable to God. Thus, the consistent evangelical theologian must maintain that human sacrifice, in and of itself, was not against the will of God, otherwise, he/she has just eliminated the possibility that the death of Christ was acceptable to God.
Dilling continues: The crucial question related to the proposed sacrifice of Isaac is this: In the death of Christ, did God actually demand the sacrifice of an innocent human being as a substitutionary sacrifice for others, thereby atoning for their sins and propitiating the wrath of a holy God against them? The dilemma which this question poses for the interpreter is: If answered affirmatively, then there is no a priori ground for denying that God could have demanded the actual slaying of Isaac as a sacrifice. Indeed, if God could demand the death of his own Son as a substitutionary sacrifice, then there is more ground for expecting Him to demand the sacrifice of other human beings than for denying the same. On the other hand, if one answers negatively, then the whole basis for Christian salvation is destroyed.( p. 28)
Dilling (pp. 27-28) believes that the sacrifices found in other religions actually derive from the revelation of the OT God to his people. He argues:
The institution of sacrifice is a primitive, savage rite that was merely tolerated for a season until more advanced revelation could be received. The latter position we reject on the grounds of our presupposition that the Holy Scriptures are an inspired and inerrant revelation, and the corollary that the religion of Israel is therefore essentially revealed rather than evolved. However, even apart from this premise, it is quite possible to establish with a relatively high degree of certitude that the origin of sacrifice must be accounted for on the basis of divine revelation. Hobart Freeman has pointed out that:” The universal prevalence of the practice of vicarious and piacular sacrifice. . .cannot be reasonably explained apart from the idea that it was derived from a common and authoritative source.” [Hobart E. Freeman, "The Doctrine of Substitution in the Old Testament" (unpublished Th.D. dissertation, Grace Theological Seminary, Winona Lake, Ind., 1961), p. 103.])
While I disagree with Dilling and Freeman on the origin of the idea of human sacrifice, I think it’s a powerful admission on their part, when they say that it was really Yahweh's idea. I believe the case is actually reversed. The concept of offering a human sacrifice to propitiate a deity originated among the Gentiles and that the Jews, while generally repulsed by the idea, understood it as the ultimate offering to a deity. That explains why the death of Jesus was later interpreted by the early followers of Jesus (who were largely Jews) as the ultimate and final sacrifice for the sins of mankind. It was, in their understanding, the climax and fulfillment of all the animal sacrifices in Judaism (see the Book of Hebrews).