Fasting is a good idea for Advent anyway. December 17th - I'm in.
Prayer and fasting is a good thing. Advent's one of those times particularly set aside where that is a good thing to do.
Never did pay a lot of attention to Josep's messages, but I know the man suffered a lot for Christ. And is a great religious artist.
My feeling about apocalyptic messages is: I am in the hands of Christ. I will pray and fast and give praises to his name, and try hard to be light and salt and leaven in a world that needs the Light, but I don't worry about the Apocalypse. Or a purification.
But these things do catch people's syes, and sometimes, it gets them thinking about what's important. And that can be a good thing.