Earliest recorded slam against Christers?

If this looks like a Christer worshipping a crucified horse to you, you would be wrong. It's actually a donkey an ass. More ancient graffiti recently translated is here.
     Unfortunately, we know the rest of the story: the Christer Cult took over the all the important civil service positions of Rome's government, converted an emperor or two, got Christianity made the state religion and eventually made life hell on wheels for pious Pagans. And when they died, their playbook eventually fell into the hands of Karl Rove.