What you describe is nihilism. And according to Neitzsche, if God is dead then all bets are off. We can do whatever we want without consequence. He died in 1900 and, as he predicted, 20th century faith in government resulted in the biggest bloodbaths in human history. When government supplants God, nothing good happens. This explains why leftist, progressive and liberal governments tolerate, or even lead, attacks on believers and traditional family. Because these two institutions are its only real competitors. Truth is, atheists don't bother me--but far too many of them behave like anti-theists. And their proselytizing sounds a lot like the words they claim to despise.