There is a fascination with the idea of “lost Gospels” or “secret Gospels” that were “suppressed” by the “theological winners.” The canon of the Bible is only in the form it is because a certain group won out, so the reasoning goes. Such reasoning may be seen from Bart Ehrman:
But where did this book [the New Testament] come from? It came from the victory of the proto-orthodox. What if another group had won? What if the New Testament contained not Jesus’ Sermon on the Mount but the Gnostic teachings Jesus delivered to his disciples after his resurrection? What if it contained not the letters of Paul and Peter but the letters of Ptolemy and Barnabas? What if it contained not the gospels of Matthew, Mark, Luke, and John but the Gospels of Thomas, Philip, Mary, and Nicodemus?Bart Ehrman, Lost Christianities: The Battles for Scripture and the Faiths We Never Knew (Oxford: Oxford University Press, 2003), 248.
Such a view, under the influence of Walter Bauer’s Orthodoxy and Heresy in Earliest Christianity, is that all Christian writings were on equal footing during the early days of the church due to the vast diversity supposedly present at the time. This view gives little to consideration of the dating of the Gospels in question. Any time anybody suggests that these apocryphal Gospels were legitimately competing with the canonical Gospels, all you need to do is point out that that the four canonical Gospels are the only four that can be dated to the first century; all others are second century or later (some scholars argue that the Gospel of Thomas is first century, but that is by far a minority position). They do not represent an independent tradition concerning Jesus, but show themselves at multiple points to be dependent upon the canonical Gospels and even responding to them in a revisionist form at times. Being later, they cannot legitimately claim to represent the apostolic teaching.
If you were to read the apocryphal Gospels, it would be fairly obvious that they derive from a completely different worldview. Since most people have never actually read any of the apocryphal Gospels, I provide here a selection of quotations that plainly show that they are incompatible with the earliest Christian writings. If you want to read the apocryphal Gospels for yourself, you may find a number of them here.
Simon Peter said to him, “Let Mary leave us, for women are not worthy of life.” Jesus said, “I myself shall lead her in order to make her male, so that she too may become a living spirit resembling you males. For every woman who will make herself male will enter the kingdom of heaven.”The Gospel of Thomas 114
Jesus saw infants being suckled. He said to his disciples, “These infants being suckled are like those who enter the kingdom.” They said to him, “Shall we then, as children, enter the kingdom?” Jesus said to them, “When you make the two one, and when you make the inside like the outside and the outside like the inside, and the above like the below, and when you make the male and the female one and the same, so that the male not be male nor the female female; and when you fashion eyes in the place of an eye, and a hand in place of a hand, and a foot in place of a foot, and a likeness in place of a likeness; then will you enter the kingdom.”The Gospel of Thomas 22
The Lord said, “Blessed is the one who exists before existing, because they who exist did exist, and will exist.”The Gospel of Philip
Some say that “Mary conceived by the Holy Spirit.” They’re wrong; they don’t know what they’re saying. When did a woman ever conceive by a woman?The Gospel of Philip
Those who say that the Lord died first and then arose are wrong, because he arose first and (then) he died. Anyone who doesn’t first acquire the resurrection won’t die. As God lives, that one would die!The Gospel of Philip
And while they were explaining to them what they saw, again they saw three men coming out of the tomb, with the two supporting the one, and a cross following them. And the heads of the two reached as far as heaven, but that of the one being led by them reached beyond the heavens. And they heard a voice from the heavens, saying, “Have you proclaimed to those who sleep?” And a response was heard from the cross: “Yes!”The Gospel of Peter 39-42
“The first [is Yaoth], who’s called ‘the Good One.’ The second is Harmathoth, [the eye of fire]. The [third] is Galila. The fourth [is] Yobel. The fifth is Adonaios. These are the five who ruled over Hades and are the first over Chaos.The Gospel of Judas
Then Saklas said to his angels, ‘Let’s create a human being after the likeness and the image.’ And they fashioned Adam and his wife Eve, who in the cloud is called ‘Life,’ because by this name all the generations seek him, and each of them calls her by their names.”
Peter said to him, Since you have explained everything to us, tell us this also: What is the sin of the world?The Gospel of Mary 4.25-32
The Savior said There is no sin, but it is you who make sin when you do the things that are like the nature of adultery, which is called sin. That is why the Good came into your midst, to the essence of every nature in order to restore it to its root.
Then He continued and said, That is why you become sick and die, for you are deprived of the one who can heal you. He who has a mind to understand, let him understand.
Matter gave birth to a passion that has no equal, which proceeded from something contrary to nature. Then there arises a disturbance in its whole body. That is why I said to you, Be of good courage, and if you are discouraged be encouraged in the presence of the different forms of nature. He who has ears to hear, let him hear.
From there he was going with his father Joseph, and someone running struck his shoulder. And Jesus said to him, “Cursed be you because of your leader!” And immediately he died. And the people who saw that he had died immediately cried out and said, “From where was this child born, that his word becomes deed?”The Infancy Gospel of Thomas 4.1-2
And when the parents of the dead child saw what had happened, they blamed Joseph his father, saying, “From wherever you have this child, you can’t live with us in this village. If you want to be here, teach him to bless and not to curse, because our child has been taken away from us.”
I’m not saying, then, that those who haven’t yet come into being are nothing, but they exist in the one who will want them to come into being when he wants, like a later time. Before everything is revealed, he knows what he’ll produce. But the fruit which he hasn’t yet revealed doesn’t yet know anything, nor does it do anything. In addition, every realm which is itself in the Father is from the one who exists, who establishes them from what doesn’t exist. For those who have no root have no fruit either. They think to themselves, “I’ve come into being,” but they’ll dissolve by themselves. Because of this, those who didn’t exist at all won’t exist.The Gospel of Truth
 For a strong refutation of Bauer’s thesis and a critique of the idea of extensive diversity, see Andreas J. Köstenberger and Michael J. Kruger, The Heresy of Orthodoxy: How Contemporary Culture’s Fascination with Diversity Has Reshaped Our Understanding of Early Christianity (Wheaton, IL: Crossway, 2010).