Epictetus, Golden Sayings 144

I am free, I am a friend of God, ready to render Him willing obedience. Of all else I may set store by nothing—neither by my own body, nor possessions, nor office, nor good report, nor, in a word, anything else beside. 

For it is not His Will, that I should so set store by these things. Had it been His pleasure, He would have placed my Good therein. But now He has not done so: therefore I cannot transgress one jot of His commands. 

In everything hold fast to that which is your Good—but to all else (as far as is given you) within the measure of Reason only, contented with this alone. Else you will meet with failure, ill success, let, and hindrance. 

These are the Laws ordained of God—these are His Edicts; these a man should expound and interpret; to these submit himself, not to the laws of Masurius and Cassius.