According to the Qur'an, after Allah (God) had completed the creation of everything else (2-29), God announced that He will create a Khalifa (vicegerent) on Earth, causing the angels to exclaim how He intends to place on earth one who shall make mischief and shed blood while they hymn His praise and sanctify Him.
http://en.wikipedia.org/wiki/Iblis

According to Islam, man is not born in 'original sin'. He is God's vicegerent on earth.
http://www.freerepublic.com/focus/news/699710/posts

The book continues with a presentation of the traditional view of man as ‘God’s Viceroy on Earth’
http://www.fonsvitae.com/kingcastle.html

I prefer not to translate the word 'khaleefah' that has different meanings as mentioned in topics of the attached URLs (in Arabic & English) unless your context explains so.

translation of the meaning

خَليفَه= successor

((Indeed I will place in earth a successor)) [2:30]
Linguistic meaning of the word successor/vicegerent (Khalifah) ——
One who succeeds another. The four rightly guided caliphs were called khaleefahs because they succeeded the prophet S.A.W. in guiding the muslim nation and ruling over them.
Contextual meanings of the word successor/vicegerent (Khalifah) — —
Human generations succeeding one after another
Implementing the law of God on earth (e.g. Allah had made Prophet David a vicegerent in earth)
Exercising delegated power on behalf of Allah in earth
The most common interpretations are 1 and 2. However, all three interpretations are correct. As for 3, that is the greatest and biggest interpretation of the quranic verse.
Allah will place in earth His successor, one who will succeed Him in might, power and authority. Deputy of the heavens and the earth, Allah’s right hand, ambassador and vicegerent in earth. The successor will have the highest rank close to Allah in the universe, and will be the most preferred creation. The fact that the successor will be higher than the Throne in status proves that he qualifies for using Allah’s divine power, because the Throne represents Power, Authority and Majesty. Allah will hand over the rule to His successor and send him to earth to exercise power on His behalf, with His agenda, while maintaining sovereignty Himself.
The successor will have to emerge at a time when repentance is no longer accepted, and when there will be no believer left on earth, after the sun rises from the west. Compared to miracles (small supernatural events that are shown by the prophets to get people to believe), the successor will be using Allah's divine power in earth, and everyone will know the truth at that point.
The fact that the successor will act on behalf of Allah indicates that the matter will be very serious. It is not befitting for Allah to descend to earth and walk among His creatures due to His Exaltedness, Majesty and Highness. That is why He will appoint His successor to do His bidding.
Allah will not be absent, as He always has, is, and will continue to observe everything in the Universe, including His successor, and has the power to revoke given authority at any time should His successor disobey His commands.
All of this indicates that Allah’s successor will bring the hour on the rest of creation in earth, complete destruction and annihilation of all living beings, and vengeance from His enemies (i.e. Satan and his allies). When the successor completes his objective, he will have to ascend to the heavens to return Allah’s divine power and rule back to Him, before the second blow in the trumpet (resurrection). At this point the fate of Allah’s successor is unknown, will he taste death or stand beside the Throne when Allah calls out, and (afterwards) descend alongside Allah to the land of gathering.
No creation in the universe has ever worshipped Allah the way He deserves, not even the angels. In order to worship Him the way He deserves one must be exempt from His fear and use His divine power. To be exempt from His fear one must outmatch all of His favours and bounties which He has bestowed. To be able to use His divine power one must be higher than the Throne and Footstool in rank, and the Successor is the only creation that will be able to achieve this.
Since worship elevates one in status, the successor will have the highest position among creation, above the Universe close to Allah, and will worship Him in front of Him. The successor will be at Allah’s side forever, witnessing everything He does, will be involved with His affairs with His creation (i.e. given tasks), and will enforce His commands on the rest of His creation. Most importantly, the successor will know all of Allah’s names and attributes and their nature, as well as the secrets of the universe.
The successor will be the most preferred, jealous and powerful creation. He will have no equal from among the creation. The only human being that is higher than all the prophets and messengers in status. The messengers and prophets were merely humans who's job were to warn and give glad tidings to the people, and feared Allah. The successor will not even fear Allah, and thus will be the most feared creation in the Universe.
So will the successor be a temporary god? The answer is no, because there is no object/entity worthy of being worshipped except Allah. Even if the successor assumes control over the heavens and the earth, that does not qualify him for worship.
So how will the successor succeed Allah? Be careful, Allah does not have a successor when it comes to his Godship (Al Uluhiyyah), because there is no other god worthy of being worshipped. Had Allah taken a son (which is impossible), that son would have succeeded in worship.
Rather, the successor will succeed the Almighty in His Lordship (Al Ruboobiyyah). So in essence, the successor will be a temporary Lord, and not a temporary god.
Can the successor overthrow the King? Not a chance because firstly, Allah's knowledge encompasses everything and secondly, the universe would cease to exist without His presence.
The successor will be the only creation that will be exempt from the Prophet's intercession on the last day, because he will be higher than the Prophet in status and his abode will be above the Universe close to Allah, next to the throne.
Also, the successor will be the only creation that will have the right to be arrogant as a slave, because he will be able to worship Allah the way He deserves. Satan was casted out of Allah's mercy for being arrogant because the reason for his arrogance was unacceptable.
The successor is satan's nemises and will be coming to kill him and his army when the time arrives.
(فإنّك من المنظرين. إلى يوم الوقت المعلوم) [Al Hijr: 38]
Indeed you (satan) are from among those who are given respite. Until an appointed time.

As for the knowledge of how to outmatch Allah's bounties and favours, I cannot share that with anyone. Allah has already reserved this high rank for someone.