One of the great Gnostic Church leaders was Clement of Alexandria in Egypt (150-211 A.D.), who indicated that he possessed the secret teaching handed down from the apostles.
The Gnostic text entitled The Secret Gospel of Mark, one of the Christian Gnostic texts discovered in 1945, describes Jesus performing secret initiation rituals. Before the discovery of this secret gospel, our only knowledge of it came from a letter written by Clement. Clement quotes from this secret gospel and refers to it as "a more spiritual gospel for the use of those who were being perfected." He also states, "It even yet is most carefully guarded [by the church at Alexandria], being read only to those who are being initiated into the great mysteries." Clement mentions elsewhere that Jesus revealed a secret teaching to those who were "capable of receiving it and being molded by it" He also affirmed that, "The gnosis (secret knowledge) itself is that which has descended by transmission to a few, having been imparted unwritten by the apostles." (Miscell. Book VI, Chapter 7)
The existence of a secret teaching can be found in the New Testament:
Paul wrote about teachings which are taught to spiritual "babies," teachings about righteousness for the more mature, and then teachings for the spiritually mature. Paul reveals this fact immediately after equating Melchizedek to Jesus by stating:
"We have much to say about this, but it is hard to explain because you are slow to learn. In fact, though by this time you ought to be teachers, you need someone to teach you the elementary truths of God's word all over again. You need milk, not solid food! Anyone who lives on milk, being still an infant, is not acquainted with the teaching about righteousness. But solid food is for the mature, who by constant use have trained themselves to distinguish good from evil. (Heb. 5:11-14)
According to tradition, after the Roman invasion of Jerusalem, the author of the Gospel of Mark established a church in Alexandria, Egypt. Mark may also have been the author of a "secret gospel" containing more advanced teaching for those being initiated into the Christian mysteries. This secret gospel contains passages portraying Jesus teaching secret doctrines.
The Champion for the Secret Teachings of Jesus
As the orthodox church in Rome gained more and more political power the more it viewed secret teachings as a threat to their own public teachings. But the Church leader who made the final and greatest attempt to revive the secret teachings of Jesus within the orthodox teachings was the first Church Father named Origen (183-253 A.D.) of Alexandria in Egypt, who was a disciple of Clement of Alexandra. Origen was the first person since Paul to develop a system of theology around the teachings of Jesus. His effort was the first within the orthodox church to systematize a theology on so vast a scale. Although Origen defended orthodoxy, he included in his system the wisdom of the Christian Gnostics. His theology was a perfect synthesis of "orthodox" and "gnostic" teachings and came the closest to reviving the "lost Christianity" of the original sects, communities and schools, at a time when the Christian Gnosticism was falling into disrepute. Unfortunately, hundreds of years later, the Church declared him a heretic and his teachings as heresy mostly because they affirmed preexistence and therefore reincarnation.
Origen had this to say about the secret teachings of Jesus:
[Jesus] conversed with His disciples in private, and especially in their sacred retreats, concerning the Gospel of God; but the words which He uttered have not been preserved, because it appeared to the evangelists that they could not be adequately conveyed to the multitude in writing or in speech and they saw what things were to be committed to writing, and how this was to be done, and what was by no means to be written to the multitude, and what was to be expressed in words, and what was not to be so conveyed. (Contra Celsus, Chap. VI. 18)
Concerning these secret teachings, Clement stated:
James the Righteous, John and Peter were entrusted by the Lord after his resurrection with the higher knowledge. They imparted it to the other apostles, to the seventy. (Outlines Book VI)