the assumption of unity

From the International Standard Bible Encyclopedia:

The basal conception for the Bible doctrine of atonement is the assumption that God and man are ideally one in life and interests, so far as man’s true life and interest may be conceived as corresponding with those of God. Hence, it is everywhere assumed that God and man should be in all respects in harmonious relations, “at-one.” Such is the ideal picture of Adam and Eve in Eden. Such is the assumption in the parable of the Prodigal Son; man ought to be at home with God, at peace in the Father’s house (Luke 15). Such also is the ideal of Jesus as seen especially in John 14 through 17; compare particularly 17:21ff; compare also Ephesians 2:11-22; 1 Corinthians 15:28. This is quite possibly the underlying idea of all those offerings in which the priests — God’s representatives-and the people joined in eating at a common meal parts of what had been presented to God. The prohibition of the use of blood in food or drink is grounded on the statement that the life is in the blood (Leviticus 17:10 f) or is the blood (Genesis 9:4; Deuteronomy 12:23). Blood was used in the consecration of tabernacle, temple, vessels, altars, priests; all things and persons set apart for Yahweh. Then blood was required in offerings made to atone for sin and uncleanness. The reason for all this is not easy to see; but if we seek an explanation that will account for all the facts on a single principle, shall we not find it in the idea that in the life-principle of the blood God’s own life was present? Through this life from God all living beings shared God’s life. The blood passing out of any living being must therefore return to God and not be consumed. In sprinkling blood, the life-element, or certainly the life-symbol, over persons and things set apart for God they were, so to say, visibly taken up into the life of God, and His life extending over them made them essentially of His own person. Finally the blood of sacrifices was the returning to God of the life of the man for whom the beasts stood. And this blood was not burned with the dead sacrifice but poured out beside the holy altar. The now dead sin offering was burned, but the blood, the life, returned to God. In peace-offerings of various sorts there was the common meal in which the common life was typified.

In the claim of the first-fruits of all crops, of all flocks and of all increase, God emphasized the common life in production; asserted His claim to the total life of His people and their products. God claimed the lives of all as belonging essentially to Himself and a man must recognize this by paying a ransom price (Exodus 30:12). This did not purchase for the man a right to his own life in separation from God, for it was in no sense an equivalent in value to the man’s time. It the rather committed the man to living the common life with God, without which recognition the man was not fit to live at all. And the use of this recognition-money by the priests in the temple was regarded as placing the man who paid his money in a sort of continuous worshipful service in the tabernacle (or temple) itself (Exodus 30:11-16).