Even though one is well advanced in virtue, should he stop mortifying himself, he soon would lose his modesty and virtue - just as fertile soul quickly becomes dry and arid and produces nothing but thorns and thistles if it is not cultivated. John Climacus
There's no dearth of kindness In the world of ours; Only in our blindness We gather thorns for flowers. Gerald Massey
Truths and roses have thorns about them. Henry David Thoreau
Не that goes barefoot must not plant thorns. English Proverb
And he repents in thorns that sleeps in beds of roses. English Proverb
The cost is high of the honey that must be licked from thorns. Dutch Proverb