Charles Pastoor and Galen K. Johnson, Historical Dictionary of the Puritans, pp. 270-271:
ROBERTS, FRANCIS (1609-1675). English Puritan preacher. Roberts was born at Methley, near the town of Leeds. He studied at Trinity College, Oxford, and became a proponent of Presbyterianism, subscribing to the Solemn League and Covenant of 1643. In that same year, Roberts became the pastor of the St. Augustine's Church on Watling Street. He served doubly as the chaplain to the Earl of Essex in Dublin, and, in 1649, he became the rector at Wrington, Somerset. His theological legacy lies chiefly in his book The Mystery and Marrow of the Bible, a massive tome that elaborates the history of God's dealings with the human race in terms of six covenants, arranged successively through Adam, Abraham, Moses, David, the Jewish exiles in Babylon, and Jesus Christ. His additional writings include Believers Evidences for Eternal Life, The Key of the Bible, and True Way to the Tree of Life.
Won Taek Lim in The Covenant Theology of Francis Roberts, pp. 3-4, writes:
Among the works of those inappropriately neglected Puritan thinkers, Roberts' immense book on covenant stands out. In 1657 Roberts published The Mysterie and Marrow of the Bible: viz. God's Covenants with Man.... Considering the size of books published at that time, it was extraordinary to write more than 1,700 pages in folio on a single subject. In God's Covenants Roberts' citation of authors ranges widely from the early church to his own days. Roberts cites St. Augustine and John Calvin more often than any individual Puritan thinkers, including the divines of the Westminster Assembly.
Roberts outlines the plan of his work ("a plan devised and partially executed by John Ball," Charles Augustus Briggs, General Introduction to the Study of Holy Scripture, p. 465, and referenced by Thomas Blake in Vindiciae Foederis; or, a Treatise of the Covenant of God Entered With Man-Kinde in his preface to the reader (1653)):
A Work of vast extent, comprising in it: all the methods of divine dispensations to the Church in all ages; all the conditions of the Church under those dispensations; all the greatest and precious promises, of the life that now is, and of that which is to come; all sorts of blessings promised by God to man; all sorts of duties repromised by man to God; all the gradual discoveries of Jesus Christ, the only Mediator and Saviour of sinners; the whole mystery of all true religion from the beginning to the end of the world; and which as a continued thred of gold runs through the whole series of all the Holy Scriptures,...because I have set my heart exceedingly to the Covenants of my God, which (in my judgment) are an universal basis or foundation of all true religion and happiness, I have shunned no diligence, industry, or endeavor that to me seemed requisite for the profitable unveiling of them.
Ernest F. Kevan, The Grace of Law: A Study of Puritan Theology, p. 116, records the diagram of God's Covenants that Roberts sets forth (p. 16, cf. pp. 177, 739 f.), which I have reformatted here:
God's COVENANT is twofoldIn 2007, I had the privilege to visit the Puritan Resource Center at Puritan Reformed Theological Seminary in Grand Rapids, Michigan, which owns a copy of Roberts' tome. A dear friend took a picture of me with that book, along with some others, including another by Roberts, The Key of the Bible (along with the Works of William Perkins and Daniel Rogers' Naaman the Syrian, his Disease and Cure). It is my prayer that one day, massive though it is, someone will take on the project of republishing God's Covenants, for the benefit of the Church, which always stands in need of a deeper understanding of covenant theology.
1. A Covenant of Works, in the first Adam, before the Fall.
2. A Covenant of faith, in the second Adam, after the Fall; comprehending [1 and 2 below].
1. The Covenants of Promise, under the Old Testament. (1) With Adam. (2) With Noah. (3) With Abraham. (4) With Israel in Mount Sinai. (5) With David. (6) With the Jews about their return from Babylon.
2. The Covenant of Performance, or the New Covenant under the New Testament.