What is the main conflict in Hudson Taylor's Spiritual Secret by Hudson Taylor?

From the text:

"Envied by some, despised by many, hated by others, often blamed for things I never heard of or had nothing to do with, an innovator on what have become established rules of missionary practice, an opponent of mighty systems of heathen error and superstition, working without precedent in many respects and with few experienced helpers, often sick in body as well as perplexed in mind and embarrassed by circumstances—had not the Lord been specially gracious to me, had not my mind been sustained by the conviction that the work is His and that He is with me in what it is no empty figure to call 'the thick of the conflict,' I must have fainted or broken down"