Nope, that is demonstratably true. Find any early church father before Ireneous' introduction of those four gospels that mentions and quotes them by name. Nobody is aware that they exist prior to this. They are fighting against the gnositcs and heretics for "supreme heretic" when they magically appear. These gospels would have been vital in their defence, but, crickets.
I know they taught you that the bible is "The very Word of God" and you believed them unquestioningly. If you continue in that belief, it is your own fault. The gospels come from an oral tradition, and when the "end is near" wasn't near, it was time to write them down. The books of your bible are different than the early church's bible, and that is different from the later church's bible, and all these different "Christians" have different books in their bible. But everyone believes that their particual selection of scripture is the correct "word of God."
The New Testament teachings were by letters and books from the beginning. We can see in 2 Peter 3:15-16 Peter recognizes what Paul writes as scripture.
2 Peter 3:15 Bear in mind that our Lord’s patience means salvation, just as
our dear brother Paul also wrote you with the wisdom that God gave him. He writes the same way in all his letters, speaking in them of these matters. His letters contain some things that are hard to understand, which ignorant and unstable people distort,
as they do the other Scriptures, to their own destruction.
Much of the New Testament is letters from the apostles to the churches, and the apostles commanded the churches to share the letters.
Colossians 4:16 After this letter has been read to you, see that it is also read in the church of the Laodiceans and that you in turn read the letter from Laodicea.
1 Thessalonians 5:27 I charge you before the Lord to have this letter read to all the brothers and sisters.
Again, the believers from the beginning used these books and letters from the start. That is what determined these books as scripture.
Luke 1:1-4 Many have undertaken to draw up an account of the things that have been fulfilled among us, just as they were handed down to us by those who from the first were eyewitnesses and servants of the word. Therefore, since I myself have carefully investigated everything from the beginning, it seemed good also to me to write an orderly account for you, most excellent Theophilus, so that you may know the certainty of the things you have been taught.
John 20:30 Jesus performed many other signs in the presence of his disciples, which are not recorded in this book. 31 But
these are written that you may believe that Jesus is the Messiah, the Son of God, and that by believing you may have life in his name.
I know the Bible is true because I did what Jesus says to do to find out.