Compiled from sermons preached in London and published two years after Charnock's death in 1680, these discourses argue first for the existence of God against atheism, then turn to his nature. Volume one runs from the proofs of God's being through practical atheism, his spirituality and the worship it demands, his eternity, immutability, omnipresence, knowledge, and wisdom. Charnock joins close reasoning to searching application, pressing each truth on the conscience as much as the mind, which is why the work shaped Puritan and Reformed theology for generations.

The second volume carries Charnock's treatment of the divine perfections from the power of God through his holiness, goodness, dominion, and patience. Each discourse builds a doctrine from a single text, defends it against objection with scholastic care, then turns it to comfort, warning, and worship. Left unfinished at his death in 1680 and gathered by his friends, the series still stands as the fullest Puritan account of who God is.