He writes:

I had a question. My brother, who is an atheist, cited Bart Ehrman's book  "Lost Christianities", where he supposed proves that New Testament was modified because the original supported heretical views. I'm not very familar with Ehram's work or early Church history. So, what do you make of such claims? Thanks and God bless!

Bart Ehrman is the sad case of an Evangelical who got enough of an education that he reached the point a friend of mine reached.  My friend said he realized “I can be a Protestant or a Christian, but I could not be both anymore.”  The mood of skeptical corrosion that ate away at all the rest of the Catholic and apostolic deposit of faith reaches, finally, the sacred book the Church proclaims at her liturgies and the Bible-only Protestant faces a stark choice: he can do like my friend and acknowledge the fundamental blunder of using the Bible as a weapon against the community that wrote, edited, and collated it—or he can do like Ehrman and deconstruct the Bible as well, in the process destroying his faith and collecting his 30 pieces of silver and bravely facing the applause of the MSM.  Chesterton describes the process this way:

For, looking back on older religious crises, I seem to see a certain coincidence, or rather, a set of things too coincident to be called a coincidence After all, when I come to think of it, all the other revolts against the Church, before the Revolution and especially since the Reformation, had told the same strange story. Every great heretic had always exhibit three remarkable characteristics in combination. First, he picked out some mystical idea from the Church's bundle or balance of mystical ideas. Second, he used that one mystical idea against all the other mystical ideas. Third (and most singular), he seems generally to have had no notion that his own favourite mystical idea was a mystical idea, at least in the sense of a mysterious or dubious or dogmatic idea. With a queer uncanny innocence, he seems always to have taken this one thing for granted. He assumed it to be unassailable, even when he was using it to assail all sorts of similar things. The most popular and obvious example is the Bible. To an impartial pagan or sceptical observer, it must always seem the strangest story in the world; that men rushing in to wreck a temple, overturning the altar and driving out the priest, found there certain sacred volumes inscribed "Psalms" or "Gospels"; and (instead of throwing them on the fire with the rest) began to use them as infallible oracles rebuking all the other arrangements. If the sacred high altar was all wrong, why were the secondary sacred documents necessarily all right? If the priest had faked his Sacraments, why could he not have faked his Scriptures? Yet it was long before it even occurred to those who brandished this one piece of Church furniture to break up all the other Church furniture that anybody could be so profane as to examine this one fragment of furniture itself. People were quite surprised, and in some parts of the world are still surprised, that anybody should dare to do so.

My friend chose the sane route and became a Catholic.  Ehrman chose the popular route and now writes rubbish such as the book you describe.

Here’s the facts: Jesus, recall, says “This is the new covenant (diatheke, also translated “testament”) in my blood”. Indeed, the *only* time Jesus uses the word diatheke in all four of the gospels is at the institution of the Eucharist.   If you asked a Christian in the first two centuries of the Church what the “new diatheke” was, they would have pointed you, not to the books we call the New Testament, but to the Eucharist.  The New Testament documents we have derive their very name from the fact that they were in close liturgical proximity to the Eucharist.  The New Testament we have was compiled by the Church on a rather simple basis: they came from “apostles and apostolic men” and reflected the common life, worship and teaching of the Church as it was received from the apostles.  In short, the answer to the question “By what right did the Church get to decide which books go in the Bible?” is the same as the answer to the question, “By what right do you get to decide which pictures go in your family photo album?”  It’s your family photo album, dude.  You can include and leave out what you like.  The books in the New Testament reflect the faith that comes to us from the apostles.  They are, very simply, the books read at the liturgy in which the "new diatheke in my blood" is celebrated..

Now it’s true that there are books representing “lost Christianities” in the sense that the they are “Christian” and not Confucian, Buddhist, Zoroastrian, or Aztec heresies. So, for instance, the sundry Gnostic heresies cooked up books like the gospel of Judas or the gospel of Thomas which mixed in a few genuine quotes from Jesus with various esoteric sayings placed on the lips of Jesus by the Gnostic sectarian who doesn’t like apostolic teaching and wants to improve on it. Thomas sees Jesus as a talking head.  Judas’ only interest in the death of Jesus is as proof that the body is of no importance.  Indeed, the typical hallmark of a false gospel is that it tends to ignore completely the core of the canonical gospels: namely, the passion, death, and resurrection of Jesus--and therefore the "new covenant in my blood".  That’s because Gnostics tend to loathe the created world and regard it as the work of an evil god, which Jesus came to rescue us from by liberating us from the disgusting icky body through secret knowledge.  It’s partly in response to incipient Gnostic thinking that John bangs away at “the Word became flesh” in his gospel and warns that “anyone who denies that Jesus Christ has come in the flesh is antichrist” in his first epistle.  In short, the illusion that Ehrman is trying to create is that Christianity began as a small group of completely equal and legitimate sects with theories about who Jesus was and what his life meant and then, by dumb luck, the sect called the Catholic Church happened to win out.

Rather, what happened was, well, pretty much what the gospels describe. There was one body, one Lord, one faith, one baptism, one apostolic Church founded on the Twelve with Christ as the cornerstone. Jesus picked 12 apostles and said, “He who listens to you listens to me”.  That’s because, despite the curious postmodern assurance that somebody with a reputation as a mystic must be a clueless git about matters of common sense, Jesus was not, in fact, a clueless git.  If there was anything he was absolutely certain about and was constantly reminding his followers of, it was the fact that he was going to die and was not always going to be there.  So he made provision for that fact by picking out twelve men and making sure they would carry on his message.  Were there other enthusiasts for Jesus of varying thought and quality?  Absolutely.  The gospels record this.  So do Acts and the epistles.  Jesus was, in fact, acutely aware of this.  That’s why, when Jesus asked, “Who do people say I am?” there was no shortage of popular opinion to draw from, just as there is now.  Some were like Apollos and preached Jesus in enthusiastic ignorance.  Like Apollos, these guys were welcomed by the apostolic church and taught “the way of God more accurately” by people like Aquila and Priscilla.  Some cast out demons in Jesus' name and, when John tried to stop them "because they do not belong to us" Jesus rebuked, not the exorcists, but John, saying, "Do not stop them, for he who is not against us is for us" ( a lesson for Rad Trads who are cocksure that anybody outside the visible Church is surely damned).  Some, like Simon Magus, didn’t get it and saw Jesus as a way to power and influence (Acts 8). Peter had harsh words for this.  Others didn’t like Paul or one of the other apostles and preached Jesus in the hope of making trouble for them.  Others regarded Jesus’ name as a magical incantation.  Still others denied he was ever a human being (a favorite gnostic theme).  And that’s just a small sample of the ways he was misunderstood.

The apostolic nature of the Church was, in the end, why it survived and the sundry Gnostic sects did not.  What is interesting is that these “lost Christianities” (that is, heresies) died out on their own.  The Church, recall, had no state power.  It was, in fact, itself persecuted when the various Gnosticisms came and went.  The Gnostic gospels went out of print, not because the Church suppressed them, but for a very simple reason: nobody was reading them.  In an age where books required hand copying, people were not inclined to preserve books nobody cared about.  So places like the Nag Hammadi library didn’t get burned.  They just got neglected, rather like the East Side Public Library in Detroit.