This Bible contradiction is from the EvilBible.com.
Christ's witness of himself is true
John 8:14 View context
Jesus answered and said unto them, Though I bear record of myself, [yet] my record is true: for I know whence I came, and whither I go; but ye cannot tell whence I come, and whither I go.
John 8:18 View context
I am one that bear witness of myself, and the Father that sent me beareth witness of me.
Christ's witness of himself is not true
John 5:31 View context
If I bear witness of myself, my witness is not true.