In other words, the Church existed before the Bible and gave itself the Bible: it is hence logically problematic to claim that the Church is founded on the Bible or to set the Bible over the Church.
This argument, which is traditionally followed out to the conclusion that we can only be sure what to believe if we listen to the Pope and his bishops, is put to rather different use by liberals:[T]he Christian Church comes before the Bible and itself established its extent and composition.
These include various miscellaneous Church documents which still survive: a letter written by the leader of the church at , for example, and a manual of teaching called the Didache.
They also include the ‘New Testament apocrypha’ - documents written some time later than the canonical NT books which were influenced by or set out to imitate them.
These include a number of apocryphal gospels, such as the famous Gospel of Thomas.