The works that presented themselves as "authentic" but did not obtain general acceptance from within the churches, are called New Testament Apocrypha. These are not accepted as canonical by most mainstream Christian denominations; only the Ethiopian Orthodox Church recognizes the Shepherd of Hermas, 1 Clement, Acts of Paul, and several Old Testament books that most other denominations reject, but it should be noted that this church does not adhere to an explicit canon. But i've read some and some are reasonable for example 'Select Sentences of Sextus the Pythagorean'. Though there are others. http://en.wikipedia.org/wiki/New_Testament_apocrypha
http://www.sacred-texts.com/cla/gvp/gvp09.htm
http://www.sacred-texts.com/cla/gvp/gvp09.htm