"The gospel claims that Christ was neither crucified nor was he God’s son. Instead, it says he was just a prophet. The book also refers to Apostle Paul as “The Impostor” and further claims that Christ ascended back to heaven alive, with Judas Iscariot being crucified in his place."
They are accurate and nice information. But as I said, if his book contains the narrative of Barnabas, it is the book of hadith. Just like Matthew, Bukhari or John.
But if it contains the words of God directly like the Qur'an, it is the Gospel.