Nicene and Post-Nicene Fathers, Ser. II, Vol. VII:
Select Letters of Saint Gregory Nazianzen.: Letter LXXXI

Ep. LXXXI.

You are distressed by your travels, and think yourself unsteady, like a stick carried along by a stream.  But, my dear friend, you must not let yourself feel so at all.  For the travels of the stick are involuntary, but your course is ordained by God, and your stability is in doing good to others, even though you are not fixed to a place; unless indeed one ought to find fault with the sun, for going about the world scattering his rays, and giving life to all things on which he shines; or, while praising the fixed stars, one should revile the planets, whose very wandering is harmonious.