No that is not certain at all. There are different views on the matter but one of the views held by scholars is that they were written by the disciples who claimed to author them partially as eye witness accounts and partially through the testimonies of eye witnesses all in the 1st century.
Additionally Jewish male literacy was in fact high and assuming they were illiterate is also wrong.
You have made an number of assumptions and errors in your reply. Simply put it appears as though you have a bias or an agenda here. There is an accepted scholarly view that these documents were written by who they claim to be and are broadly historically accurate.