He did not fail to confess, but confessed freely, I am not the Christ.
The literal Greek is 'and he confessed and denied not and he confessed' I am not a Greek scholar so I assume this is a figure of speech meaning he denied vehemently that he was the Christ (or Messiah). To John it would have been blasphemy to claim to be such. With great vehemence he denies it. Remember how the Apostle was shocked when the Gentiles wanted to worship him. No man should claim to be God and should anyone imply such a thing we should shrink from it with alacrity.