Following Cerinthus of Ephesus in the first century, there arose in the second an eastern orthodox Christian, Marcion, who would embrace a form of Gnosticism that would produce several early church polemicists to counter his influence. This was a golden era of Christian literature written by many apologists to combat this and other heresies, as well as criticisms leveled at the orthodox Christian church. Men like Irenaeus, Tertullian, and Cyprian, would loom large upon the pages of early church history as great defenders of the Christian faith. It would be they who would eventually dissect orthodox Christianity apart from the heresy of Gnosticism.

Meanwhile, it was this Cerinthian Gnostic, Marcion, who would be dubiously credited for the separation of the Jewish Old Testament from the Christian writings that had been previously added to expand and complete it. It was he who would produce the first separate New Testament document apart from the Jewish Canon, which he flatly rejected. Marcion's Bible included The Gospel (as written by Luke and redacted by Marcion himself to bring it in line with his theological persuasions) and The Apostle (ten letters of Paul whom he considered the only legitimate apostle true to Christ's teachings). His divisions would be adopted and expanded by the orthodox church as it attempted to counter his efforts. The orthodox church would expand The Gospels and Apostles, adding also the Pastoral Epistles, thus arriving upon a form and number that later would become finalized and continue to present day as our New Testament.

Besides canonization of scripture, other methods to counter Gnosticism emerged through attempts to define mainstream Christianity as it had evolved from its roots in apostolic times. First, to refute the Gnostic philosophic idea of intermediary agents as continuing imparters of God's wisdom for man's salvation, an appeal was made to the authority of tradition. (Compare: II Pe.3:14-17: I Jn.1:1-7; Jude 3). From this practice evolved a leadership considered in succession of the apostles themselves, leading to what became commonly known as the Episcopate, and eventually the Catholicism that has survived to modern times.

Secondly, one sure way to guarantee exclusion of the Gnostic (or any other heretic for that matter) from membership and worship, was to adopt a creed that was contrary to their beliefs and in line with mainstream Christianity. These creeds were composed and adapted into the emerging liturgy of the churches. Notice in the following earliest known example the preciseness of wording to attest to the orthodox doctrines of Christ:

I believe in God the Almighty Father,
And in Christ Jesus his Son,
Who was born of the virgin Mary,
Crucified under Pontius Pilate and buried,
Who arose from the dead on the third day,
Ascended into the heavens,
Sits at the right hand of the Father,
From whence he shall come to judge the living and dead,
And I believe in the Holy Spirit, (and) the resurrection of the flesh.
(Baker, p. 32)

Traces of this creedal practice can be seen today in almost every denomination, church, or affiliation in some form or another. Some are identified as creeds and are rigidly enforced, while others are simply called statements of faith (such as those of the Baptists) and are commonly ascribed to by affiliating churches and its members.