No greater pride is there than judging others, nor is there anything for which God abandons man, more than for judging others. Everywhere in the Scriptures God tells us clearly not to judge others, but rather ourselves. Likewise spiritual writers condemn this fault of judging others with so many examples that the day would sooner be over than we could relate just a few of them. Take this thought for a conclusion: the beginning of the ruin of the spiritual life is judging others.
-- Saint Anthony Mary Zaccaria from a sermon