What are the devil's usual effects?

What are [the devil's] usual effects? ... He is often called diabolos in the Greek of the New Testament, a word derived from dia-balein, (to throw apart, to scatter). God is a great gathering force, for by his very nature he is love; but the devil’s work is to sunder, to set one against the other. Whenever communities, families, nations, churches are divided, we sniff out the diabolic. The other great New Testament name for the devil is ho Satanas, which means “the accuser.” Perform a little experiment: gauge how often in the course of the day you accuse another person of something or find yourself accused. It’s easy enough to notice how often dysfunctional families and societies finally collapse into an orgy of mutual blaming. That’s satanic work.

Bishop Robert Barron,

Word on Fire Bible, commentary on Mark 6:6-13