Georg Christoph Lichtenberg, The Waste Books, tr. R. J. Hollingdale, New York Review Books, 1990, p. 112, Notebook G, Aph. #24:
To make man as religion wants him to be resembles the undertaking of the Stoics: it is only another grade of the impossible.
I agree completely with Herr Lichtenberg that the Stoic ideal is an impossible one.
The Stoic sage would be as impassible as God is impassible. But here's something to think about: Jesus on the cross died in agony like a man, even though, if he was God, he could have realized the Stoic ideal.
What is the lesson? Perhaps that to be impassible is for us impossible, and so no ideal at all.
What Lichtenberg overlooks is that while Stoicism is a self-help therapeutic, religion, or at least Christianity, is not: no Christian who understands his doctrine fancies that he is able by his own power to effect genuine, deep-going, and lasting self-improvement.
What Lichtenberg fails to appreciate is that what is impossible for us, both individually and collectively, is not impossible with divine assistance.
If you deny the possibility of divine assistance, then you ought to abandon the project of ameliorating in any truly fundamental way the human condition: just accept it as it is, else you may end up like the Communists who murdered 100 million in the 20th century alone in quest of their u-topia.