And they brought one. And he said to them, "Whose likeness and inscription is this?" They said to him, "Caesar's." Jesus said to them, "Render to Caesar the things that are Caesar's, and to God the things that are God's." And they were amazed at him.

Mark 12:16-17

You will never enjoy the sweetness of a quiet prayer unless you shut your mind to all worldly desires and temporal affairs.

- St. Norbert of Xanten