Does taking means always guarantee results in worldly matters, or are results dependent on the will of Allah? And does this differ between worldly and religious matters? What is the preponderant view on this issue between the Ash'arite school and the People of Hadith?

It is part of Allah Almighty's wisdom to link causes with their effects. However, the existence of a cause does not necessarily mean the inevitable existence of the effect, as there might be an impediment preventing its occurrence. For instance, fire burns, but it did not burn Ibrahim (peace be upon him). Supplication (du'a) is a cause for a response, like other good deeds and causes. Allah has made the response contingent upon it, just as an effect is contingent upon its cause. Causes do not operate unless their conditions are met. For example, fire burns what is susceptible to burning, and the sun illuminates what is capable of reflecting its rays. The linking of effects to causes encompasses both worldly and religious matters.