This so-called gospel and numerous others like it, such as the Gospel of Thomas, are considered to be false documents because they teach things at odds with orthodox Christianity. Such books often date to many centuries after the life of Christ and they contain teachings that are clearly influenced by Gnosticism and Greek Neo-platonism.
Only the 66 books of the Holy Bible are considered to be God-breathed, “given by inspiration of God and profitable for doctrine, for reproof, for correction, for instruction in righteousness” (2 Tim 3:16)
Read more on this: How Can We Be Certain the Bible was Inspired by God? Learn the Bible: Books of the Bible-Fast, Fun, Short Video Summaries