82% of the words of Jesus are not his:

"The Five Gospels," is a 550 page book containing translations of the Gospels of Matthew, Mark, Luke, and John. It was the result of a six year study by 24 Christian scholars from a number of Western universities. They decided to produce a translation of the Gospels which would be uncolored by the translator's personal faith. It was decided that this translation was to give the reader an honest picture of what Jesus truly said. They scanned the text for the words of Jesus, and collect an index of over 1,500 such sayings. They then tested the validity of each of these sayings, one at a time, to see whether Jesus truly said each one. They then produced a fresh translation, color-coded to show authentic Jesuit sayings and those of an unreliable nature. Their conclusion (page 5) was:

"Eighty-two percent of the words ascribed to Jesus in the gospels were not actually spoken by him."

They go on to reveal that:

"biblical scholars and theologians alike have learned to distinguish the Jesus of history from the Christ of faith. It has been a painful lesson for both the church and scholarship. The distinction between the two figures is the difference between a historical person who lived in a particular time and place...and a figure who has been assigned a mythical role, in which he descends from heaven to rescue humankind and, of course, eventually returns there."

Well then, if 82% of the "words of Jesus" found in the Bible were apparently never spoken by him then where did they come from? Some of the sources demonstrated by the authors are:

"The concept of plagiarism was unknown in the ancient world. Authors freely copied from predecessors without acknowledgment. Sages became the repository of free-floating proverbs and witticisms. For the first Christians, Jesus was a legendary sage: it was proper to attribute the world's wisdom to him. The proverb in Mark 2:17, for example, is attested in secular sources (Plutarch and Diogenes for example)...in the parallel to the Markan passage, Matthew adds a sentence taken from the prophet Hosea (Matt 9:13)."

Also:

"Hard sayings are frequently softened in the process of transmission to adapt them to the conditions of daily living...Variations in difficult saying often betray the struggle of the early Christian community to interpret or adapt sayings to its own situations... Matthew's version of the aphorism "The last will be first and the first last"(Matt 20:16) is softened in Mark 10:31 to "MANY of the first will be last, and of the last MANY will be first"."

And probably most revealing:

"Christian conviction eventually overwhelms Jesus: he is made to confess what Christians had come to believe...The contrast between Christian language or viewpoint and the language or viewpoint of Jesus is a very important clue to the real voice of Jesus, the language of Jesus was distinctive, as was his style and perspective."