The writings attributed to Justin Martyr are extremely significant because they show that Acts of the Apostles, the Pauline Corpus and even the Catholic Epistles were UNKNOWN and also show that the Gospels were NOT yet attributed to Matthew, Mark, Luke and John.
If one examines the NT Canon the FOUR Gospels are almost always first then followed by Acts of the Apostles, The Epistles and Last the Revelation of John.
Acts of the Apostles and the Epistles are compiled in 22 books.
So of the 27 books of the NT Justin Martyr did NOT know 22 books of the Existing Canon.
But it gets even worse Justin Martyr did NOT know that Four Gospels were attributed to Matthew, Mark, Luke and John.
Essentially, Justin Martyr, a Christian writer supposedly in the mid 2 century, only knew or acknowledged ONE single book in the NT Canon--the Apocalypse of John.
Amazingly, Justin Martyr did NOT identify any Gospels according Matthew, Mark, Luke and John, did NOT identify Acts of the Apostles and did NOT identify any Epistle of Paul, James, Jude, Peter and to the Hebrews.
Justin Martyr a Christian writer identified ONLY the Apocalypse of the supposed Apostle John.
Justin Martyr goes from the Memoirs of the Apostles to Revelation.
Justin Martyr does NOT know 26 books of the NT Canon.
How is it possible that Justin did NOT identify 26 of the 27 books of the NT Canon and made ZERO references to the NAMED authors?
The answer is extremely easy--a piece of cake.
The Four named Gospels, Acts of the Apostles, and the 21 epistles in the NT Canon were NOT yet invented in the time of Justin.
This will be confirmed in writings attributed to Celsus in Origen's "Against Celsus".
According to Origen, Celsus [a Skeptic of antiquity] wrote AGAINST Christianity in a book called "True Discourse".
"True Discourse" is believed to have been written c 175-180 CE.
Now examine the quotes from "True Discourse" according to Origen.
http://www.earlychristianwritings.com/text/celsus.html
1. No Gospel is identified by Celsus as according to Matthew, Mark, Luke and John.
2. No Epistle is identified by Celsus under the names of Paul, James, Peter, John and Jude.
3.There are No accounts of the Apostles by Celsus which is mentioned in Acts.
Writings attributed to Christians and Skeptics in the 2nd century knew NOTHING of the Four NAMED Gospels, Nothing of Acts of the Apostles, and NOTHING of the 21 Epistles in the existing NT Canon.
But, this is found in Celsus' "True Discourse"--
Christians of antiquity had CORRUPTED the Gospel in order to answer objections.
Origen's "Against Celsus"
27. [Celsus' Jewish critic]: The Christian believers, like persons who in a fit of drunkenness lay violent hands upon themselves, have corrupted the Gospel from its original integrity, to a threefold, and fourfold, and many-fold degree, and have remodeled it, so that they might be able to answer objections.
The NT CANON is a MANY-FOLD corrupted version of the Gospel.
The NT Canon is a REMODELED product.
The NT Canon is WITHOUT the original integrity.
The NT Canon is historical RUBBISH.
Examine the historical RUBBISH in "Against Heresies" where the Gospel was CORRUPTED and REMODELED.
The authors of "Against Heresies" CORRUPTED and REMODELED the Gospel to answer objections by the so-called Heretics.
.....He was above forty years old, and that He certainly was not one of only thirty years of age.For it is altogether unreasonable to suppose that they were mistaken by twenty years, when they wished to prove Him younger than the times of Abraham.