The Gospel of Jesus (Injeel) is the book of The God revealed to Prophet Jesus (Isa, عليه السلام). Like the Torah, many people make the mistake of stating The Gospel is the New Testament of today’s Bible, which is far from the truth. The New Testament consists of written work attributed to some of Jesus’ disciples and not to Jesus himself. And a good portion of the New Testament was written by Paul, who was not even a disciple of Jesus at all.
Most modern scholars have concluded it is highly unlikely that Jesus’ actual disciples wrote any part of the New Testament. Even if they had written it (which they did not) there is nothing to confirm how much of its text contains the original text that was revealed to the Jesus (عليه السلام). While, there may be portions of the original revelation or the import of its meaning in the compiled writings, popularly known as the Gospels of Mark, Luke, John, and Matheus, it is clearly mixed up with human content.
The only Gospel that we are concerned with, is the Gospel of Jesus. But like all other books, the actual text is no longer available to us to even refer to in its original form, not to say of its meaning and interpretation. The language that Jesus spoke (Judean dialect of Aramaic) also is now obsolete and is no longer spoken or understood fully and completely.
However, like all of the other Books of The God, the message of the Gospel of Jesus (The Injeel) is testified and preserved in the message of the Qur’an.