Jesus is revealing who He is, who sent Him, what His mission is, that He must die and rise from the dead.  The Pharisees challenge Him and cry blasphemy.  But, there were some Judean (Jews) who believed in Him.  Jesus addresses them, and as He continues teaching, a big argument ensues, and they repudiate Him.  But....how did they once believe in Him.  They wanted to choose what to believe about Jesus - fit Him into their belief system, instead of listening to the truth.  A similar problem occurs in our society today.  People are quick to jump on the Jesus bandwagon and believe about Him what they will - and still call themselves Christian.  Many people today, want to fit Jesus into their own construct of who He is and call themselves Christian.... What can we say about what WE believe and confess about Jesus.