The hostile forces have a certain self-chosen function: it is to test the condition of the individual, of the work, of the earth itself and their readiness for the spiritual descent and fulfilment. At every step of the journey, they are there attacking furiously, criticising, suggesting, imposing despondency or inciting to revolt, raising unbelief, amassing difficulties. No doubt, they put a very exaggerated interpretation on the rights given them by their function, making mountains even out of what seems to us a mole-hill. A little trifling false step or mistake and they appear on the road and clap a whole Himalaya as a barrier across it. But this opposition has been permitted from of old not merely as a test or ordeal, but as a compulsion on us to seek a greater strength, a more perfect self-knowledge, an intenser purity and force of aspiration, a faith that nothing can crush, a more powerful descent of the Divine Grace.
Ref: Letters on Yoga – IV