In 1674 John Owen wrote a preface for a work by the congregationalist preacher Samuel Petto entitled The Difference between the Old and New Covenant Stated and Explained: With an Exposition of the Covenant of Grace in the Principal Concernments of it. In this note to the "Christian Reader" Owen elaborates upon the significance of the divine covenants (of Works and Grace) for a proper understanding of Scripture and a right relationship with God. He even states that next to the sending of Christ to redeem sinners, no other doctrine accentuates God's grace and advances God's glory than the Covenant of Grace - of course, for Owen, the ministry of Jesus and God entering into covenant with men are inextricably related.
Here is a sample:
The stores of heavenly wisdom, grace, and truth which are treasured up in the divine revelations concerning God's covenants, are far from being fully exhausted or drawn forth by the labours of any in this kind. Although very many have already brought to light excellent and useful instructions in the mind of God and the duty of them who do believe. But the thing itself is so excellent, the mystery of it so great, the declaration of it in the Scripture so extensive and diffused throughout the whole body of it from the first to the last, as also in its concernment unto the whole course of our faith and obedience, that there is a sufficient ground whereon to justice a renewed search into the mind of God therein as revealed in his word.
There is no doubt, but the greatest product of divine grace, goodness, and condescension, next unto the sending of the only Son of God to take our nature on him...is this of his entering into covenant with the children of men; nor hath any thing a greater tendency unto the advancement of his own glory.