“Absolutely under the Old Testament, it consisted only in Promise, and as such only is proposed in the Scripture, Acts 2.39. Hebrews 6.14, 15, 16. The Apostle indeed says, that the Covenant was confirmed of God in Christ; before the giving of the Law, Gal. 3.17. And so it was not absolutely in itself, but in the Promise and Benefits of it. The nomethesia, or full legal establishment of it, whence it became formally a Covenant unto the whole Church, was future only, and a Promise under the Old Testament.”
“It wanted its solemn confirmation and establishment by the blood of the only Sacrifice which belonged unto it. Before this was done in the death of Christ, it had not the formal nature of a Covenanl or a Testament, as our Apostle proves, Chap. 9.15-23.”
“[The new covenant] is neither a Renovation of [the old] Covenant, nor a Reformation of it, but utterly of another nature, by whose introduction and establishment that other was to be abolished, abrogated and taken away, with all the Divine Worship and Service which was peculiar thereunto.”
~ John Owen
via Samuel Renihan’s From Shadow to Substance