The Bible teaches that the Devil is real. God said so in His Word, throughout the pages of history.
The Devil was an angelic being created by God. Ezekiel stated he was an anointed Cherub which is the highest order of Angelic hosts. Cherubs, Cherubim, Serephim, Archangel, angels, etc.
Ezek 28:14-15...Thou art the anointed cherub that covereth; and I have set thee so: thou wast upon the holy mountain of God; thou hast walked up and down in the midst of the stones of fire.Thou wast perfect in thy ways from the day that thou wast created, till iniquity was found in thee.
Isaiah the Prophet called him Lucifer...who rebelled against the supreme authority of God... the Creator of all things.
Isa 14:12-14...O Lucifer, son of the morning! how art thou cut down to the ground, which didst weaken the nations! For thou hast said in thine heart, I will ascend into heaven, I will exalt my throne above the stars of God: I will sit also upon the mount of the congregation, in the sides of the north: I will ascend above the heights of the clouds; I will be like the most High.
In Genesis 3:15 he was called "the serpent" that deceived Eve in the Garden of Eden. This is the reason why the curse of the fall has plagued the human family since the "Original Sin". For by the disobedience of one... many were made sinners.
The Bible teaches that the Devil is not omnipresent as many people think...
Job 1:7...And the LORD said unto Satan, Whence comest thou? Then Satan answered the LORD, and said, From going to and fro in the earth, and from walking up and down in it.
Matthew 4 said Jesus was tempted of the Devil while fasting in the Wilderness.
Jesus spoke of the Devil (when accusing the Pharisees) in
John 8:44...Ye are of your father the devil, and the lusts of your father ye will do. He was a murderer from the beginning, and abode not in the truth, because there is no truth in him. When he speaketh a lie, he speaketh of his own: for he is a liar, and the father of it.
Jesus stated the Devil was "from the beginning". The Bible does not plainly teach when the beginning was.
According to Peter the Devil is one of our greatest oppositions in life...
1 Peter 5:8...Be sober, be vigilant; because your adversary the devil, as a roaring lion, walketh about, seeking whom he may devour:
The Devil can be considered the God of this Age or the God of this period of time before Christ Raptures the Church...
2 Cor 4:4...In whom the god of this world (Age) hath blinded the minds of them which believe not on the Gospel
The Devil who is also the accuser of the Brethren in the presence of God will be cast out of Heaven during the middle of the seven year Tribulation. This event has not happened yet!
Rev 12:9-10...And the great dragon was cast out, that old serpent, called the Devil, and Satan, which deceiveth the whole world: he was cast out into the earth, and his angels were cast out with him. And I heard a loud voice saying in heaven, Now is come salvation, and strength, and the kingdom of our God, and the power of his Christ: for the accuser of our brethren is cast down, which accused them before our God day and night.
The Apostle John stated that the Devil was a sinner from the beginning. Christ came to "destroy" the works of the Devil.
1 John 3:8...He that committeth sin is of the devil; for the devil sinneth from the beginning. For this purpose the Son of God was manifested, that he might destroy the works of the devil.
God's Judgement has been placed on the Devil "after the Tribulation". Satan will be bound for 1000 years.
Rev 20:1-2...And I saw an angel come down from heaven, having the key of the bottomless pit and a great chain in his hand. And he laid hold on the dragon, that old serpent, which is the Devil, and Satan, and bound him a thousand years,
When the 1000 years expire Satan is loosed (for a short time) to deceive many nations...
Rev 20:7-8...And when the thousand years are expired, Satan shall be loosed out of his prison, And shall go out to deceive the nations which are in the four quarters of the earth, Gog and Magog, to gather them together to battle: the number of whom is as the sand of the sea.
Then comes "God's Final Judgement of the Great White Throne" where the wicked dead are resurrected and judged... and the devil is cast into the lake of fire for Eternal Punishment...
Rev 20:10...And the devil that deceived them was cast into the lake of fire
The question was asked, "Is the Devil real". Yes! The Bible says so! God said so! All that said about the Devil to say this one thing...Submit yourselves to God...resist the Devil and he will flee...Why will the Devil flee? He has no authority. God has "all" authority. That's why the Devil has to flee from the child of God. The child of God is in subjection to the authority of Christ. Christ has all authority! Glory!