In De prophetae officio (1532) Bullinger wrote (sig. Aivv-Avr): “For testament, which also is the title for all of Scripture, surely strands for the content of all Scripture. Neither is this to be wondered at as something recent and devoid of meaning. For by the word testament we understand the covenant and the agreement by which God agreed with the entire human race, to be himself our God, our sufficiency, source of good and horn of plenty. And this he would abundantly prove by the gift of the fertile earth and the incarnation of his son. Man, however, ought to pursue integrity, that he may stand before this God with a perfect and upright mind, that he may walk in his ways and commit himself totally to him, as to the highest and most loving Father”.
Hence Bullinger concludes that the covenant is “the source of our religion and the first chapter of it” (haec nimirum religionis nostrae origio & illud caput primarium est).