There are two words to choose from, "forgery" or "pseudepigrapha."
The word forgery is used when there is criminal intent and the intent removes the rights of someone else. Recent examples of forgeries were the Hitler diaries and the biography of Howard Hughes. In both of those cases, the creators were trying to gain money.
The word pseudepigrapha is used for people who create religious documents and use the name and authority of others to give credence to the document.
With pseudepigrapha there is not criminal intent, as the people doing this kind of activity usually see themselves as inspired by deities, spirits or deceased people. It is difficult, if not wrong, to include writers of biblical or Chinese material in the same category as the desperate con artist who forges a signature on a check or creates a document from Shakespeare and tries to sell it to make money. Indeed, if there had been a court case in 300 AD about such documents, the accused would say that they had been divinely inspired, and that would have been considered a completely valid defense that would have been investigated based on the person's past behavior.
Did the person create the documents and then try to sell them to accumulate wealth? Did they use them to start their own religion and collect money or deceive others or assume positions of power?
The word pseudepigrapha has a neutral feeling. Forgery does not; it is definitely negative.
I disagree with the person who says that pseudepigrapha is a euphemism for forgery.