Courtesy of the Pinacoteca Sabauda, Torino, Italy/Mauro Magliani/Superstock

Gazing down on the world, God seems capable of knowing every person, event, thought or idea in his creation. Only a slight shadow across his brow in this painting by Italian artist Giovanni Francesco Guercino (1591–1666) indicates there might be limits to God’s wisdom.

The Bible is more ambiguous, as Michael Carasik points out in the accompanying article. Certain verses seem to portray God as all knowing; he “hears” the unspoken thoughts concealed in the hearts of men. But elsewhere God must test individuals to find out what they are really thinking.