"WHAT IS THE GOSPEL PROPERLY SPEAKING? And although our fathers had the Gospel in this way in the writings of the prophets by which they attained salvation in Christ through faith, yet the Gospel is properly called glad and joyous news, in which, first by John the Baptist, then by Christ the Lord himself, and afterwards by the apostles and their successors, is preached to us in the world that God has now performed what he promised from the beginning of the world, and has sent, nay more, has given us his only Son and in him reconciliation with the Father, the remission of sins, all fulness and everlasting life. Therefore, the history delineated by the four Evangelists and explaining how these things were done or fulfilled by Christ, what things Christ taught and did, and that those who believe in him have all fulness, is rightly called the Gospel. The preaching and writings of the apostles, in which the apostles explain for us how the Son was given to us by the Father, and in him everything that has to do with life and salvation, is also rightly called evangelical doctrine, so that not even today, if sincerely preached, does it lose its illustrious title."
(The Second Helvetic Confession, Chapter XIII)