But conversion does not put the brain on automatic pilot. Nor is it like a sudden brain transplant. Therefore, forgiveness of sins was unique to the new covenant. The old covenant was made at Sinai when Israel accepted its terms. The new covenant is made at baptism when we accept Christ's sacrifice and commit ourselves completely to God and His will.
Eternal life is more than a chronological event and change of composition.
The change of composition is only a means to that end. After He returns to set up the kingdom of God, Christ will establish the new covenant with all Israel and ultimately all mankind. This shows The Law remains an integral part of the new covenant. Some wrongly assume that all Old Testament laws are obsolete unless repeated in the New Testament. The New Testament is a record of members living by the terms of the new covenant.