Did Jesus tell lies in John 10:27-28 when He said,
I am not sure if Jesus said ANYTHING that is attributed to Him in the Gospels, that He did has to be taken on faith.
If we assume that He did say everything attributed to Him in the Gospels, and if we assume He was not insane, then the only reasonable conclusion is that Jesus lied a lot of the time.
There's also ample evidence that Jesus was a particularly nasty child, He even murdered another child, so perhaps He is not as nice as people would like Him to be.
But, it all depends how we treat the sources, if we are blind unthinking robots then we accept everything at face value, but if we can think for ourselves, and we are truly interested in finding out the truth, then we will have a more critical approach to the sources.