Fitnah: The Pitfalls of Disquieting Doubt 57:14
They will address them, were we not with you? They will confirm. However, you deceived and mislead your own soul. You waited and you doubted. It is what you desired and yearned for that deceived you. All of this occurred until G-d and his judgment was decided. His is wrath always proves to be true.
Disquieting doubt can cause mankind to lose his way, when he allows himself to be allured by unchecked desires. Trials and temptations will encourage him to go against the dictates of G-d. In doing so, he pulls himself out of the heavenly position he was created for. Without having a desire to please his Lord, he succumbs to low desires. Such desires might consist of achieving rank and status, lust of the flesh, or obtaining wealth--all at any cost. These unchecked desires began to carry more weight than G-d’s higher calling, which He offers us through scripture.
Ultimately, such deviations come with a price. Just as the mother disciplines her child for disobeying, she stills extends mercy. G-d shows His mercy by giving man a taste of punishment. A prime example can be shown in how iron ore is refined.
In the refinement process, fire is applied as a way of purification. Sometimes, the process has to be done several times, but never to the melting point. It is up to the Ironsmith (The Creator in this case,) on how He chooses to shape and mold it after the impurities are burnt off. Fortunately, the virtuous servants are mindful of temptation. Whatever obstacles they are faced with, they never allow low desires to cause them to displease G-d.