Indeed. Who, objectively, should one believe? The modern liberal proponents of “higher criticism,” which is itself a German enlightenment philosophical construct which represents basically an abstract reality, opinion as fact, or the historical-factual statements of people like St. Irenaeus of Lyons who were bishops in the very early church, who were connected by just a few generations to the Apostles, and who had a vested interest in proving which works were in fact genuine (since it was the genuine apostolic works which contained the true doctrine, and the Gnostic forgeries which contained the distortions; there was no middle ground - the early church happily accepted works not of apostolic provenance that contained true doctrine, like The Shepherd of Hermas, but classified them separately from those works known to be of apostolic origin, like the Pastoral Epistles).
When in doubt, we should always look to the early church for guidance, because it was the early church that wrote the new testament, implemented the liturgical rites, developed the canons of normal Christian behavior and appropriate pastoral conduct, and also decreed the definitive New Testament canon.