Faith
In any religious text, faith is an important theme (or, in some cases, non-faith). This is because the main goal of a religious text is to gain more converts and convince existing followers that the religion is the only one that is true. If you have full faith in the religion, according to the religion, you will live a fuller, richer, happier life. The Gnostics were killed, and their writings were almost all burned.
Power Corrupts
No one can say that power does not corrupt. Every once in a while, someone will do what is best for others, but, for the most part, they will do what is best for themselves. In the case of the Orthodox Church, they have been corrupted. The Gnostics told them that they had too much power, and the Church killed them and burned their writing.
Freedom Of Speech
You should be able to say what you want to say to who you want to say it as long as it does not harm them. This privilege was not given to the Gnostics. They wrote a text that they deemed to be sacred, and the Orthodox Church proceeded to persecute them. This really isn't fair behavior, but the Church had more power than them, and was able to do what they did.
