The book of Job speaks of the "sons of God," which is another way to speak of angelic beings.
"Now there was a day when the sons of God came to present themselves before the Lord, and Satan also came among them." Job 1:6
Satan appeared before God with the "sons of God" and that indicates he is an angelic being. All angels were originally in heaven, but it is believed that when Satan rebelled and was cast out of heaven, he took up to 1/3 of the angels with him.
"The great dragon was hurled down—that ancient serpent called the devil, or Satan, who leads the whole world astray. He was hurled to the earth, and his angels with him." Revelation 12:9
Satan can appear as an angel of light, or "good": "And no wonder, for Satan himself masquerades as an angel of light." 2 Corinthians 11:14
Angelic beings are creations of God, so they are not eternal. They had a beginning. They are God's work (creation).
Psalm 103
19The Lord has established His throne in the heavens,
And His sovereignty rules over all.
20 Bless the Lord, you His angels,
Mighty in strength, who perform His word,
Obeying the voice of His word!
21 Bless the Lord, all you His hosts,
You who serve Him, doing His will.
22 Bless the Lord, all you works of His,
In all places of His dominion;
Bless the Lord, O my soul!
Satan is not omnipotent. Christians do not believe that Satan is equal in power to God. The only power that Satan has is what God allows him to have. The Book of Job shows that Satan could only go as far as God would allow him to go.
"And the Lord said to Satan, 'Have you considered my servant Job, that there is none like him on the earth, a blameless and upright man, who fears God and turns away from evil?' Then Satan answered the Lord and said, 'Does Job fear God for no reason? Have you not put a hedge around him and his house and all that he has, on every side? You have blessed the work of his hands, and his possessions have increased in the land. But stretch out your hand and touch all that he has, and he will curse you to your face.' And the Lord said to Satan, 'Behold, all that he has is in your hand. Only against him do not stretch out your hand.' So Satan went out from the presence of the Lord." Job 1:8-12
And the Lord said to Satan, “Have you considered my servant Job, that there is none like him on the earth, a blameless and upright man, who fears God and turns away from evil? He still holds fast his integrity, although you incited me against him to destroy him without reason.” Then Satan answered the Lord and said, “Skin for skin! All that a man has he will give for his life. But stretch out your hand and touch his bone and his flesh, and he will curse you to your face.” And the Lord said to Satan, “Behold, he is in your hand; only spare his life.” Job 2:3-6
Satan even asked for permission to sift the apostle Peter like wheat (whatever that means - but it doesn't sound good). Jesus told Peter about this.
“Simon, Simon, behold, Satan demanded to have you, that he might sift you like wheat, but I have prayed for you that your faith may not fail. And when you have turned again, strengthen your brothers.” (Luke 22:31-32, ESV)
Satan is not omniscient. He had Pharaoh order the deaths of the Israelite baby boys because he did not know which child would be the one to lead the Israelites out of slavery to the Egyptians. He had Herod order the deaths of the baby boys in Bethlehem because he did not know which child was the Messiah that the magi came to see.
While there are not any texts to show you here, it only makes sense when one studies the slaughter of the Israelites in Egypt and then again in Bethlehem that Satan was trying to destroy the Deliverer in each case. He knew the prophecy told to him by God in Genesis:
The Lord God said to the serpent,
“Because you have done this,
cursed are you above all livestock
and above all beasts of the field;
on your belly you shall go,
and dust you shall eat
all the days of your life.
I will put enmity between you and the woman,
and between your offspring and her offspring;
he shall bruise your head,
and you shall bruise his heel.” (Genesis 3:14-15, ESV)
He didn't even know how Jesus would react to any of the temptations that he placed before Him.
Then Jesus was led up by the Spirit into the wilderness to be tempted by the devil. And after fasting forty days and forty nights, he was hungry. And the tempter came and said to him, “If you are the Son of God, command these stones to become loaves of bread.” But he answered, “It is written,
“‘Man shall not live by bread alone,
but by every word that comes from the mouth of God.’”
Then the devil took him to the holy city and set him on the pinnacle of the temple and said to him, “If you are the Son of God, throw yourself down, for it is written,
“‘He will command his angels concerning you,’
and
“‘On their hands they will bear you up,
lest you strike your foot against a stone.’”
Jesus said to him, “Again it is written, ‘You shall not put the Lord your God to the test.’” Again, the devil took him to a very high mountain and showed him all the kingdoms of the world and their glory. And he said to him, “All these I will give you, if you will fall down and worship me.” Then Jesus said to him, “Be gone, Satan! For it is written,
“‘You shall worship the Lord your God
and him only shall you serve.’”
Then the devil left him, and behold, angels came and were ministering to him. (Matthew 4:1-11, ESV)
The Book of Revelation identifies Satan as the Dragon and as the Serpent (as in Garden of Eden).
"The great dragon was hurled down—that ancient serpent called the devil, or Satan, who leads the whole world astray. He was hurled to the earth, and his angels with him." Revelation 12:9
Satan is limited to only being able to be in one place at one time but he has been around since his creation. Satan can't be in God's presence and on the earth at the same time.
Now there was a day when the sons of God came to present themselves before the Lord, and Satan also came among them. The Lord said to Satan, “From where have you come?” Satan answered the Lord and said, “From going to and fro on the earth, and from walking up and down on it.” Job 1:6-7
And the Lord said to Satan, “Behold, all that he has is in your hand. Only against him do not stretch out your hand.” So Satan went out from the presence of the Lord. Job 1:12
Any time a human encountered an angel (Abraham, Joshua, the Apostle John are good examples) the angel told the human not to worship him, unless it was The Angel of the Lord, which is a theophany, or appearance of God on earth.
And the angel said to me, “Write this: Blessed are those who are invited to the marriage supper of the Lamb.” And he said to me, “These are the true words of God.” Then I fell down at his feet to worship him, but he said to me, “You must not do that! I am a fellow servant with you and your brothers who hold to the testimony of Jesus. Worship God.” For the testimony of Jesus is the spirit of prophecy. (Revelation 19:9-10, ESV)
I, John, am the one who heard and saw these things. And when I heard and saw them, I fell down to worship at the feet of the angel who showed them to me, but he said to me, “You must not do that! I am a fellow servant with you and your brothers the prophets, and with those who keep the words of this book. Worship God.” (Revelation 22:8-9, ESV)
Now, with regard to the earth being surrendered to Satan, you are correct. Adam was God's regent on earth, but when he stood by passively while Satan twisted God's word to Eve and then submitted to eating the fruit, Adam gave up rule over the earth and Satan gained it. That is one reason he is called "the god of this world" by Paul (2 Corinthians 4:4) and "the ruler of this world" by even Jesus (John 12:31).
And even if our gospel is veiled, it is veiled to those who are perishing. In their case the god of this world has blinded the minds of the unbelievers, to keep them from seeing the light of the gospel of the glory of Christ, who is the image of God. (2 Corinthians 4:3-4, ESV)
“Now is my soul troubled. And what shall I say? ‘Father, save me from this hour’? But for this purpose I have come to this hour. Father, glorify your name.” Then a voice came from heaven: “I have glorified it, and I will glorify it again.” The crowd that stood there and heard it said that it had thundered. Others said, “An angel has spoken to him.” Jesus answered, “This voice has come for your sake, not mine. Now is the judgment of this world; now will the ruler of this world be cast out. (John 12:27-31, ESV)
The perfect life, sacrificial death, and resurrection of Jesus ended Satan's rule over this planet, but the planet is still under the curse of sin at this time until Jesus' return.
In order not to be too lengthy, I'll just post a link to Revelation chapter 5
http://www.esvbible.org/Revelation+5/The scroll that no one is worthy to open except the Lamb is believed to be the Title Deed to the Earth, which Adam gave up when he ate the fruit. One clue is that since Jesus was the only one worthy to open the scroll, it was a very, very important document. Another clue is that He has already died and was resurrected, so He has already defeated Satan, even if Satan is still allowed to roam for awhile longer.
Again, I am only sharing the mainstream Christian view for clarification. i hope the addition of the verses and some of the additional comments help you see where Christians form their opinions about Satan.