All Christian works, including the Bible, were written centuries after Jesus was said to have lived. Before the Bible was put together there were at least double the gospels in circulation being taught as part of the Christian faith. Some of the excluded books were more popular than the books that were included in the Bible. The Bible was put together by a group of priests who wanted the Christian church to be taught their way. They put together the Bible using the books that backed their ideas of Christianity. They excluded at least half of the texts because they didn't agree with what they taught. This goes against the modern Martin Luther based Christianity.
Martin Luther believed that every one should be able to interpret the Bible for themselves. He was right. Before him, the church would choose what would be taught, and obeyed. Martin Luther recognized that the church lied about a lot of it. Now people are free to read the Bible and decide for themselves. They can and should interpret the Bible how they see it, and not how others tell them to.
This should go along with the excluded works of the Christian faith. If you believe in God and Jesus, and you accept the Bible, then you should read the other texts to get a full and educated understanding of all aspects of Christianity. The Bible is only one source.
A lot of people claim that the excluded works are but mere fakes. They might be right. We don't know yet. The Bible might be fake too. It probably is. We don't know yet, but as a faith people should read all Christian texts to get a full idea. As I said, all the texts, including the Bible, were written centuries after Christ existed. Some of them might be fakes, others might be true, and as far as we know the priests who put the Bible together faked some of the books to help back up what they wanted people to believe. We don't know.
If you view the Bible as honest, then you aught to look at the other books. Weather you wind up believing them or not, read them first. You might get a new idea of your faith, and it might not change at all, but to discredit them before you read them, and study them, is wrong. Don't judge a book by its cover. (Pun intended)
They are the "word of god" and they are perfect and you cant just pick and choose the ones beneficial for you. That includes the one that says that only men go to heaven after they die. So you cant just cherry pick whatever benefits you the most. Plus more stuff for people with critical thinking skills to disprove.
Just because a bunch of 4th Century cranks did not like those Gospels as they did not suit their Personal Political Goals of Dominance, is no reason to shut them out. They are equally as relevant as nay of the Bibles the cranks chose for inclusion into the Bible. So essentially they are equal to the Bible, likely as equally Wrong, but Equal, none the less.
The biggest thing that seems to be missed is that the bible was written by people. Interpreted by people,and rewritten by people. Political motivations change over time and no one can refute the catholic church was heavily political for an extended period of time. So by taking the modern version of the bible at face value is a mistake because more than likely the content is not no the same as the original if there even was original content as pinValentine said. We don't know and unless wecan go back in time we never will know
There are some books of the Bible that are intended for teaching, and then there are some books that are intended as records. For example, a Pastor would not pull a month's worth of sermons from the book of Numbers, or Deuteronomy. The Gnostic Gospels and other texts absolutely should be included in Biblical studies, but I think they should be examined at a personal level, rather than professed from the pulpit.