And I will make My covenant between Me and you, and will multiply you exceedingly....As for Me, behold, My covenant is with you, and you shall be a father of many nations.... I will make you exceedingly fruitful; and I will make nations of you, and kings shall come from you. (Gen 17,2.4.6)

The first covenant of Gen 15 was to confirm God's promise to Abram about the Promised Land, and as we have mentioned, it would not have been made at all if Abram had not demanded some proof from God. He asked "by what means shall I know that I shall receive it (= the land)?" So God asked him to enter a covenant by taking the animals and sacrificing them. It was sealed by means of their shed blood, as was the custom with the most important covenants at that time.

The second covenant, however, is different. First of all, God refers to it as "his (own)". This means that it arose out of God's sovereign purpose, and Abram was in no sense the initiator, only the recipient of it. Its primary content is not the land (which is mentioned only once), but focuses on the offspring itself. Abram becomes the progenitor of even many nations! This covenant was not made with the shedding of animal blood, but of man (Abram), because circumcision is necessary to include the participants in the covenant. As we have seen, this characterizes their new status, we might even say, their transformation; by participating in the covenant, Abram's descendants become something new, higher than before.  

In these two covenants with Abram God's plan of salvation and his dealings with man in all of human history has been expressed. The first covenant came to fulfillment in the formation of the nation Israel, announcing its departure from Egypt and entry into the Promised Land. This covenant thus includes the Old Testament period with its law and animal sacrifices in the earthly temple of Jerusalem.

The second covenant, which was in God's intention from the beginning and is therefore called "His" covenant, then came to its fulfillment through the shed blood of a man - God's son Jesus Christ. It is fulfilled in the followers of God who do not leave physical Egypt but spiritually "this world". Through personal transformation (which is symbolized by circumcision of heart, see Col. 2:11) they set out on a higher path. This covenant encompasses the New Testament period in which a single and final sacrifice was made, after which no more were required. The people of many nations - the participants in the covenant - are not brought to a particular land, but to eternity.

For if the blood of bulls and goats and the ashes of a heifer, sprinkling the unclean, sanctifies for the purifying of the flesh, how much more shall the blood of Christ, who through the eternal Spirit offered Himself without spot to God, cleanse your conscience from dead works to serve the living God? And for this reason He is the Mediator of the new covenant, by means of death, for the redemption of the transgressions under the first covenant, that those who are called may receive the promise of the eternal inheritance. (Heb 9,13-15)