There are many ancient writings from the period following the establishment of the New Testament faith. This is merely one of the latest to be translated and made public. It is popular because people are always looking for an excuse to discredit the Bible and thereby disparage the truth about Jesus Christ. After all, if we could convince ourselves that the Bible isn't true, then we can just live any way we please and have no concern about a coming judgment.
We believe that God is powerful enough to preserve the essential elements of His Word intact throughout the centuries. We have this inspired Word available to us today in what we commonly call The Bible. Any other material that contradicts what has already been plainly established in the Bible is automatically disqualified from becoming part of the canon. The Gospel of Judas is therefore disqualified.