The song "Judas" can be interpreted in various ways. One interpretation follows the fact that the term "Judas" means "betrayer", and not necessarily the betrayer of Jesus. If the term "Judas" is used this way, the song might be about how even though [Lady GaGa] is being betrayed several times by her lover, she still loves him or her. The song could also be about temptation. "Jesus is my virtue" is a line that explains how she isn't really trying to be a bad person, but that "Judas is the demon I cling to", sometimes she is tempted by bad things. As you can see, the song is open for much interpretation.
