In 1850 Hong Xiuquan began his religious revolt against the Qing Dynasty in China, claiming that he was "The Younger Brother of Jesus". 14 years later the rebellion was crushed as Qing Armies, with the support of Britain, France, and some other Western Mercenaries, the latter groups having grown to feel that the Taiping's were too dangerous after they attempted to take the port of Shanghai.
The negative views of Westerners in China towards the Taipings which helped lead to that Heavenly Kingdom's downfall though were not held by the Westerners whom first encountered the rebellion. To the Missionaries whom made up a sizable and influential plurality of Westerners in the Far East, the Taiping's were seen as an answer to their prayers, Christians (of a sort) out to overthrow the oppressive Qing and bring China to Christianity. Any failures in their dogma could, they hoped be repaired later, and then they the missionaries will have achieved their great dream of Bringing their faith to the Chinese Masses.
Importantly this view was held at least initially by many western diplomats and military officers whom were in the area. Such men as Commodore Perry, of the US Navy were very vocal about their wish to arm the Taiping Rebels. At the same time the United States, Great Britain, and France all worked to negotiate with the rebels on a diplomatic basis, if only to keep the Yangtze Trade Ports opened.
Eventually this view would be soured but in the initial years of the rebellion it was quite a powerful movement amongst the Westerners in China. But what would the effects be of material support to the rebellion in its inital phases? Would it allow the Taipings to decisively defeat the Qing? Or only extend the bloody horror several more years?