John Owen was not a Baptist. Our argument is that he sure sounded like one on many occasions (see below). To understand why the confessional Baptists of the 17th century, as well as confessional Baptists of today appeal to Owen see here…
The judgement of most reformed divines is, that the church under the Old Testament had the same promise of Christ, the same interest in him by faith, remission of sins, reconciliation with God, justification and salvation by the same way and means, that believers have under the new… The Lutherans, on the other side, insist on two arguments to prove that there is not a twofold administration of the same covenant, but that there are substantially distinct covenants and that this is intended in this discourse of the apostle…
Having noted these things, we may consider that the scripture does plainly and expressly make mention of two testaments, or covenants, and distinguish between them in such a way as can hardly be accommodated by a twofold administration of the same covenant…Wherefore we must grant two distinct covenants, rather than merely a twofold administration of the same covenant, to be intended…
Having shown in what sense the covenant of grace is called “the new covenant,” in this distinction and opposition to the old covenant, so I shall propose several things which relate to the nature of the first covenant, which manifest it to have been a distinct covenant, and not a mere administration of the covenant of grace.
John Owen Exposition of Hebrews 8:6
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