>Do you have any links to learn more about the Gnostic teachings, like the books left out of the Bible that were deemed heretical?
Before you dive into the cesspool of gnisticism, please read this.
https://www.gotquestions.org/Christian-gnosticism.htmlAnswer: There is actually no such thing as Christian Gnosticism, because true Christianity and Gnosticism are mutually exclusive systems of belief. The principles of Gnosticism contradict what it means to be a Christian. Therefore, while some forms of Gnosticism may claim to be Christian, they are in fact decidedly non-Christian.
Gnosticism was perhaps the most dangerous heresy that threatened the early church during the first three centuries. Influenced by such philosophers as Plato, Gnosticism is based on two false premises. First, it espouses a dualism regarding spirit and matter. Gnostics assert that matter is inherently evil and spirit is good. As a result of this presupposition, Gnostics believe anything done in the body, even the grossest sin, has no meaning because real life exists in the spirit realm only.
Second, Gnostics claim to possess an elevated knowledge, a “higher truth” known only to a certain few. Gnosticism comes from the Greek word gnosis which means “to know.” Gnostics claim to possess a higher knowledge, not from the Bible, but acquired on some mystical higher plane of existence. Gnostics see themselves as a privileged class elevated above everybody else by their higher, deeper knowledge of God.
To discredit the idea of any compatibility between Christianity and Gnosticism, one has only to compare their teachings on the main doctrines of the faith. On the matter of salvation, Gnosticism teaches that salvation is gained through the acquisition of divine knowledge which frees one from the illusions of darkness. Although they claim to follow Jesus Christ and His original teachings, Gnostics contradict Him at every turn. Jesus said nothing about salvation through knowledge, but by faith in Him as Savior from sin. “For it is by grace you have been saved, through faith—and this not from yourselves, it is the gift of God—not by works, so that no one can boast” (Ephesians 2:8-9). Furthermore, the salvation Christ offers is free and available to everyone (John 3:16), not just a select few who have acquired a special revelation.
cont'd at above link
Here are the opening paragraphs.