The website ‘Religious Tolerance‘ makes the following claims.
No matter how you describe yourself, you should find your beliefs and practices accurately represented in this website. Almost all other religious websites explain only the beliefs of the webmaster or sponsoring faith group. We are different: we try to explain accurately the full diversity of religious beliefs, worldviews, and systems of morality, ethics, and values. We hope that you will find our essays helpful and of interest.
They explain that ‘None of us has any formal education in theology‘, and ‘We know only a tiny bit about a wide range of religions and religious topics‘. Accordingly, they provide this disclaimer.
We will attempt to overcome our biases on each topic that we describe, by explaining each point of view carefully, respectfully and objectively. To this end, we have many of our essays reviewed by persons familiar with the issues who represent all sides of each topic. We encourage readers to Email us about any errors that they find. We do not regard any essay as fixed or complete.
This article examines a number of their claims concerning Gnosticism.
“Gnosticism consisted of many syncretistic belief systems which combined elements taken from Asian, Babylonian, Egyptian, Greek and Syrian pagan religions, from astrology, and from Judaism and Christianity. They constituted one of the three main branches of early Christianity:” (source)
False. Gnosticism was not ‘one of the three main branches of early Christianity’. It certainly did not pre-date Christianity.   It did even not exist as a religious movement in the 1st century.
“Simon Magus: He was one of the earliest Gnostics He was skilled in the arts of magic. He interpreted the Garden of Eden, exodus from Egypt and the crossing of the Red Sea as allegories.” (source)
False. There is no evidence at all that Simon ‘was one of the earliest Gnostics’. The earliest texts associating Simon with Gnosticism do not appear until the mid-2nd century, and are considered unreliable for the purpose of establishing what Simon really believed.  There is certainly no evidence as to how Simon interpreted the garden of Eden, the Exodus, or the crossing of the Red Sea.
False. Christianity in the 1st century was neither influenced nor infiltrated by Gnostic beliefs and leaders.   
This article was emailed to ‘Religious Tolerance’ on 5 June, 2010. Expressing thanks for the information, they advised that technical difficulties prevented them from editing the pages promptly. To date the pages have not been corrected.
 ‘Egypt has yielded early written evidence of Jewish, Christian, and pagan religion. It has preserved works of Manichaean and other Gnostic sects, but these are all considerably later than the rise of Christianity.’, Unger, ‘The Role of Archaeology in the Study Of the New Testament’, Bibliotheca Sacra (116.462.153), (1996)
 ‘Even if it could be proven that any of the previously discussed works or, for that matter, any of the NH tractates are non-Christian Gnostic documents, that would not in itself be evidence for pre-Christian Gnosticism.’, Combs, ‘Nag Hammadi, Gnosticism and New Testament Interpretation’, Grace Theological Journal (8.2.207-208)
 ‘And even if we are on solid ground in some cases in arguing the original works represented in the library are much older than extant copies, we are still unable to postulate plausibly any pre-Christian dates.’, McRae, ‘Nag Hammadi and the New Testament’, pp. 146–47, in Combs, ‘Nag Hammadi, Gnosticism and New Testament Interpretation’, Grace Theological Journal (8.2.208)
‘But it is now widely agreed that the quest for a pre-Christian Gnosticism, properly so called, has proved to be a wild goose chase.’, Dunn, ‘The Cambridge Companion to St. Paul’, p. 9 (2003)
 ‘If in all likelihood, with the possible exception of the Simonians, there was no such thing as a rival Gnostic movement within or competing with Pauline Christianity, the question arises whether there ever was a specific Gnostic myth as an entity of its own.’, Lüdeman, ‘Primitive Christianity: A Survey of Recent Studies and Some New Proposals’, p. 151 (2003)
 ‘From the 2nd–4th cent A.D. Simon came to be regarded as the father of GNOSTICISM (IrenaeusAdvhaer i.23.2, 27.1; Epiphanius Haer. xxi.7.2; xxvii.2.1). It is a matter of scholarly debate, however, whether the historical Simon was actually a Gnostic.’, Bromiley, ‘The International Standard Bible Encyclopedia’, volume 4, p. 516 (rev. ed. 2002)
 ‘There is much dispute about Simon Magus’ relationship to Gnosticism and, in particular, to the 2nd-cent. sect of Simonians, to whom, rather than to Simon himself, the Apophasis is prob. to be ascribed.’, Cross & Livingstone, ‘The Oxford Dictionary of the Christian Church’, p. 1513 (3rd rev. ed. 2005)
 ‘Questions concerning the religious-historical evaluation of Simon Magus (the father of Gnosticism?) can hardly be answered with any certainty now.’, Balz & Schneider, ‘Exegetical Dictionary of the New Testament’, volume 3, p. 245 (1990)
 ‘It is precarious, as Edwin Yamauchi and others have shown, to assume gnostic backgrounds for New Testament books. Although the phrase, “falsely called knowledge,” in 1 Timothy 6:20 contains the Greek word gnosis, this was the common word for knowledge.’, Liefeld, ‘1 Timothy 2:12 – A Classicist’s View’, in Mickelsen, ‘Women, Authority & The Bible’, p. 246 (1986)
 ‘The full-fledged Gnosticism of later church history did not exist in the first century A.D.21 An incipient form of Gnosticism was present, but Schmithals makes the error of reading later Gnosticism into the first century documents.’, Schreiner, ‘Interpreting the Pauline Epistles’, Southern Baptist Journal of Theology (3.3.10), (Fall 1999)
 ‘Some modern researchers suggest that several NT and related texts evidence contact with “Gnosticism” in various stages of its development. Texts that especially stand out are Paul’s Corinthian correspondence, Colossians, Ephesians, the Pastoral Epistles, Jude, 2 Peter, and the letters of Ignatius of Antioch (d. ca. 115) and Polycarp of Smyrna (d. ca. 165) among others. But even here the issues discussed are diverse, demonstrating a complex assortment of competing new religious movements, but no evidence of “Gnosticism.”’, Freedman (ed.), ‘Eerdmans Dictionary of the Bible’, p. 509 (2000)
 ‘Scholarship must in all likelihood abandon the hypothesis that a cohesive Gnostic movement204 is reflected in Paul’s letters.’, Lüdeman, ‘Primitive Christianity: A Survey of Recent Studies and Some New Proposals’, p. 150 (2003)