"Then Hashem answered Iyov from the storm..." At the moment Hashem revealed Himself to Iyov, the debate was over. Hashem's Presence proved that Hashem is mashgiach on all the details of mankind to the extent that He had listened to Iyov's words, and revealed Himself to debate with him and teach him knowledge. This disproved Iyov's assertion that Hashem is not mashgiach on the details of mans' life. Hashem's Presence also proved that the nefesh is man is everlasting, and is a part of Hashem; otherwise, it would be impossible to explain the possibility of Hashem talking with man who is housed in an earthly body. When Iyov felt the presence of Hashem, and understood how his nefesh is separate from his body, and is capable of clinging to Hashem and enjoying the kedushah of His Presence, all his questions about the suffering of tzaddikim were immediately answered. He now intimately understood that the essence of man is the nefesh which will ultimately separate from the body and cling to Hashem. This is the ikar of the sechar which awaits tzaddikim in the next world.
"Where were you when I founded the earth? Tell me if you know understanding."
Hashem began to account the goodness of His hashgacha and hanhaga from the beginning of Creation. He wanted Iyov to recognize that in order to understand Hashem's ways and His chochmah, he must become aware of the beginning of creation to understand the foundation of the world and its existence. He should become aware of the incredible wisdom of Hashem which exists in every minute detail of the world and its continued existence.
"In all your day, did you command the morning? Did you tell the dawn its place? ... Which way is the light parted, which way does the eastern one spread it over the earth?"
Hashem instituted that the sun shouldn't rise suddenly. The morning begins only when the sun is still eighteen degrees under the view, and the light emerges slowly until the day is set. This hashgachas pratis enables a larger part of the earth to be immersed in light, and ensures that the light does not harm the eyes.
"Do you hunt the prey for the old lion, or do you fill the appetite of the young lions?"
Hashem begins to explain the concept of hashgacha on wild animals, and their sustenance. Hashem prepares the food of all the animals, from the strongest to the weakest. The old lions, which are forced to find their food by hunting, are aided by Hashem, as well as the young lions, which are too young to hunt on their own.
"Who prepares for the raven his prey, when his young cry out to Hashem, they wander for lack of food?"
Rashi quotes the Midrash Tanchuma which says that when ravens are hatched, the father does not accept them as his own since they are born white, and he refuses to feed them. Hashem Himself feeds the young by creating gnats from their dung.
"Do you know the time for the mountain goat to give birth? Do you wait for the hinds to calve?"
Rashi says the hind's womb is too narrow for the birth process; Hashem arranges that a snake bites her at the time of birth which opens the womb. The timing is critical; if it's a second too early or late, she would die instantly.
In summary, Hashem vividly illustrates to Iyov His hashgachas pratis on every creature in the world, spanning every small detail of their lives. Hashem closely watches over each creation from the time of conception, through its birth, its dwelling place, its need for sustenance, and its old age. The life of man, who is the most important of all living creatures - who is created in the image of Hashem, and endowed with intelligence, is surely guided by Hashem.
In addition, the wondrous miracles found in nature testify to the verity of hashgachas pratis versus a world abandoned to the solar system. Hashem is criticizing Iyov for doubting His involvement in the world, the everlasting life of the soul, reward and punishment, and techiyas hameisim. In light of the miracles inherent in nature, there is no reason to doubt the verity of techiyas hameisim.
Hashem also addressed the second question which Iyov asked about the success of reshaim. Why doesn't Hashem destroy the reshaim who are similar to wild animals and destroy civilization? Hashem responded that if this question is appropriate, another question must be asked. Why didn't Hashem create only weak animals, since the strong animals prey on the weak. According to this logic, only weak animals should have been created, but this would not be fitting for the greatness of the Creator, Who in His wisdom created strong and awesome creatures. However, Hashem ensured that weak animals will continue to exist despite the presence of stronger animals, by equipping each animal with defense means. Similarly, powerful and affluent people are found among mankind, but Hashem ensures that the weak will continue to exist, by instilling the ethics of justice and kindness within mankind.