The unum necessarium , only article of faith, which the Scripture maketh simply necessary to salvation, is this, that “Jesus is the Christ.” By the name of “Christ” is understood the king, which God had before promised by the prophets of the Old Testament to send into the world, to reign (over the Jews, and over such of other nations as should believe in Him), under himself eternally; and to give them that eternal life which was lost by the sin of Adam. Which when I have proved out of Scripture, I will further show when and in what sense some other articles may be also called “necessary.”