Can you please explain the errors present in 1 Clement, The Didache, Shepherd of Hermas, Epistle of Barnabas, Apocalypse of Peter ?
I name these because they seem to have been the ones closest to making it into the Canon which ultimately were not, at least in the New Testament.
Sure, and thank you for respectfully asking. It is much appreciated.

(Again, from the book, which is mostly CATHOLIC resources. BTW, MacArthur is only cited in areas where Catholicism is in
agreement. So others bringing him up here is a moot point.)
The epistle of Barnabas - again SECOND century, so written AFTER the canon was completed. Chapter 10:1,8 states the weasel conceives with his mouth. Chapter 10:7 states the hyena can change sex. There are other errors, but for the sake of space, I am limited.
1 Clement - Chapter 25, Clement believes the Phoenix, was a real live animal that lived for 500 years & rose from the ashes, which is false. While he was using it simply as an analogy to explain the Resurrection of Jesus, nonetheless, he was still professing it was a real live animal, which he was in error.
The Didache - Chapter 7 commands the baptizer & the baptismal candidate to fast 1 or 2 days before baptism, even though the NT has numerous examples of baptizers & the baptized performing baptism that very day, or even immediately (like the Ethiopian eunuch). It also commands believers to not fast on the same day as “they hypocrites” (unbelieving Jews), even though John the Baptist & his followers fasted just like the Pharisees did (Matthew 9:14). This last one is less important, but significant: Chapter 7 also calls to pour water on the head “three times” during baptism. Yet, Jesus commanded baptism in the
name (singular) of the Father, Son, & Holy Spirit. This signifies a believer is baptized into the
name of God, meaning baptism would be a
single “immersion” into the water, not pouring
three separate times onto the head.
Like the the Shepherd of Hermas & the epistle of Barnabas, the Apocalypse of Peter is a
second century writing. So, like them, too late to have been written by Peter & included in the NT canon. Plus, it is a gnostic “gospel,” which teaches a different (false) “gospel” than that taught in the canonical first century gospels, which Paul declared anathema for teaching. Plus, when in the text, when “Giant Jesus” comes out of the tomb, He is followed by the cross…which is walking…and begins talking! Another thing to consider, the 4 gospel accounts NEVER write about actual
Resurrection event itself. The fact that the Apocalypse of Peter, as well as many of the other later gnostic “gospel” writers do, should make us question the authenticity of its authorship, especially since the “alleged” author had been DEAD for decades, or even centuries.