The Gospel of Barnabas is an account of the life of Jesus purported to have been written by Jesus’ disciple Barnabas.The only two known manuscripts of the Gospel of Barbabus are dated to the late 16th century and were written in Spanish and Italian. Note that the four gospels included in the Christian Bible (Matthew, Mark, Luke, and John) were all written in Greek in the first century after Jesus’ life, so there is a 15 century gap between them.
The Gospel of Barnabus narrates Jesus’ ministry, much of which it echoes from the four gospels. At other times, however, it contradicts the New Testament accounts and instead leans toward an Islamic interpretation of Jesus’ identity, for instance by describing Jesus as a prophet rather than the Son of God.
Just because the gospel carries the name of one of Jesus’ disciples does not mean it was actually written by a first century follower of Jesus. Most Christian and Muslim scholars consider the work “pseudopigraphical,” meaning it was penned anonymously but attributed to an earlier historical figure to give it more weight.