"I marvel that you are turning away so soon from Him who called you in the grace of Christ to a different gospel, which is not another, but there are some who trouble you and want to pervert the gospel of Christ. But even if we or an angel from heaven, preach any other gospel to you than what we have preached to you, let him be accursed. As we have said before, so now I say again, if anyone preaches any other gospel to you than what you have received, let him be accursed. But I make known to you, brethren, that the gospel which was preached by me is not according to man"(Galatians 1:6-9,11).
It has been prophesied that in the end of time, false christs, false prophets, false teachers and instructors of heresy will rise (Matthew 24:24; Mark 13:22). These oppositions of truth in fact are wolfs disguised as sheeps, those are human beings with the evil spirit who are running the final target of heresies on God's church before the second coming of Yeshua Hamasiah. Holy Bible since early days has identified these heresy matters which affect all ages in His church, and warned us not to be trapped into the Devil's trap which perverting the truth.
"Beloved, do not believe every spirit, but test the spirits, whether they are of God; because many false prophets have gone out into the world (I John 4:1). "But there were also false prophets among the people, even as there will be false teachers among you, who will secretly bring in destructive heresies, even denying the Lord who bought them, and bring on themselves swift destruction"
(2 Peter 2:1).
It is certainly that the circulation of the book known as the "Gospel of Barnabas" has nothing to do with the Christianity. That book is a false testimony from the Gospel of Truth and represents an effort (the Devil's strategy) to pervert the fact and replace it with something which directly slanders the truth.
From its name only (The Gospel of Barnabas) seems to be an effort to cult a human being named Barnabas. We do not deny that the existence of the figure of Barnabas is noted in Holy Bible as one of disciples who after the death of Yeshua Hamasiah became a work partner of Paul. But the usage of his name for Gospel separately from the Gospel of Hamasiah obviously intended to expose a personal appearance, and this is clearly opposed against the Gospel of Truth. Galatians 1:11 affirming that Gospel is not a Gospel of man, therefore no one, except Yeshua Hamasiah, has a right to use his name for the Gospel of Truth. There are no Gospel of Matthew, Gospel of Mark, Gospel of Luke, and Gospel of John standing for each of them. Those five Gospels are enclosed in an indivisible union in the name of Gospel of Yeshua Hamasiah.