The names Devil and Satan are used in the Bible for a single being, and are derived from two words:
Devil, from the Greek "diabolos" which translates as "defamer" and "slanderer". This word appears 34 times in the New Testament.
Satan, from the Hebrew "satan" (transcribed into Greek as "satanas") which translates as "adversary", "opponent" and "enemy of good". It appears in 49 Bible verses, of which 34 in the New Testament.
In the biblical sequence the word "Satan" appears for the first time in the first book of Chronicles (21:1), where it refers to a spiritual enemy agent of Israel that moved King David to number his people, leading him to commit this great sin against God and so bringing pestilence upon the people.
However, Satan is already mentioned in the book of Job, of older origin, fourteen times in its first two chapters, and there it is clearly a single being which presented itself along with the angels ("the sons of God") before God, and its purpose was to defame the righteous Job: it was therefore a "defamer", and so the name "devil" which is given him in Greek in the New Testament also befits it.
The name Satan appears, referring to this being, in 49 Bible verses, of which 34 are found in the New Testament (the same number in which Devil appears). There is therefore no margin for any true believer to deny its existence. Although we do not have much information about it in the Bible besides that which relates to its terrible relationship with the human being, there is much about this. We will then try to give a very limited summary of what the word of God tells us concerning it.
Just like all other spiritual beings, thrones, dominions, principalities and powers in heaven and on Earth (Colossians 1:15 -16), Satan was created by God through the second person of the Trinity (which became incarnate as Jesus Christ). In Ezekiel 28:1 to 10 we have a prophecy against the "Prince of Tyre", that was thought to be a god because of his knowledge and wisdom. In parallel, this prophecy also refers to the "King of Tyre", not a man, but a spirit that inspired that prince. By the description, we realize that this is Satan:
Originally he was created "seal of perfection, full of wisdom and perfect in beaut”. In the Bible, he is never like the ugly creature designed and sculpted by artists.
“He was in Eden” (which can be translated as "delight"), “the garden of God” (not the garden created later for Adam and Eve on Earth), possibly where the throne of God was.
“Every precious stone was his covering”; “he walked back on forth in the midst of fiery stones” "on the holy mountain of God".
“The workmanship of his timbrels and pipes was prepared for him on the day he was created." In his apocalyptic visions John saw musical instruments and trumpets in heaven. (Revelation 15: 2).
“He was the anointed cherub who covers, and God established him”, that is, he protected the throne of God. This was the highest position any of God’s creatures could occupy, having more power and authority than any other.
So he was perfect and without sin from the day he was created until sin was found in him, having great wisdom and beauty (remember that spiritual beings are not sexual nor do they reproduce themselves -Matthew 22:30, Mark 12:25). He was the guardian cherub, also called “son of the morning” (Isaiah 14:12), "carrier of light" (Lucifer).
But Satan was ambitious, and despite his wisdom he also became presumptuous, wishing to make himself equal to his Creator, a completely unattainable target. At one point, "lifted up because of his beauty, he corrupted his wisdom for the sake of his splendour" (Ezekiel 28:17 NIV) and Satan declared "I will ascend to heaven ... exalt my throne ... sit on the mount of the congregation... I will ascend above the heights of the clouds ... and I will be like the Most High" (Isaiah 14:12-14).
Pursuing this purpose he led a revolt against the authority of God, in which he was followed by a third of all the angels (Revelation 12:3-4). And so the "son of the morning" (Isaiah 14:12) became Satan, "the Adversary" or "Accuser". It didn't take long for God's judgment to come upon him (Ezekiel 28:16 NIV): he lost his first home, which was the high position as the guardian of the throne of God: “Therefore I cast you as a profane thing out of the mountain of God; and I destroyed you, O covering cherub, from the midst of the fiery stones.”
Satan is now the most prominent and powerful of rebel angels, known as demons, and is the arch-enemy of God and man (Job 1-2; Matthew 13:25, 38-39; 1 Peter 5:8; 1 John 4:4; Revelation 12:1-17). Even though God had originally created him in justice, Satan sinned because of pride (Ezekiel 28:15-17; 1 Timothy 3:6). In consequence, sin entered into the universe for the first time (Genesis 3:1-5; John 8:44; 1 John 3:8) and God drove Satan out of his original position in heaven (Ezekiel 28: 16).
He retains his great intelligence (Ezekiel 28:12.17; 2 Corinthians 2:11) and power (Ephesians 6:10-12; Jude 9) and is widely represented by his demons (Ephesians 6:12; Revelation 12:7-9). Satan rules the world and can influence the believers, but only within the permissive will of God (Job 1-2, especially 2:6; Luke 4:6; John 12:31; Acts 26:18; 1 Corinthians 10:13; 1 John 5:19). Christ judged Satan at the cross (John 12:31; Hebrews 2:14; 1 John 3:8; Colossians 2:15), but the final execution of this judgment will occur when he is cast into the lake of fire, where he will remain forever (Revelation 20:10).
In the middle of the period of the tribulation, Satan will be precipitated on the Earth (Revelation 12:9), but shortly thereafter will be tied up and thrown into the "abyss", after the second coming of Christ (Revelation 20:1-3). At the close of the Millennium he will be released for a short time on Earth and then cast into the lake of fire and brimstone, where he will be tormented day and night, together with the beast and the false prophet, forever and ever (Revelation 20:7-10).
Finally, we can now explain how Satan is illustrated by the old serpent:
There are passages of Scripture where we must acknowledge the so-called "law of double reference". That is, two things or persons are addressed in one passage, requiring some insight to distinguish them. In Genesis 3:15 we have the first occurrence of this law: one was the serpent, a visible material being, the other was Satan, a spiritual and invisible being, which plotted for the fall of man inspiring the serpent to deceive Eve.
The seed of the serpent is its natural descendants, and, in the spiritual sphere the seed of Satan is wicked men (John 8:44; 1 John 3:8-10). The seed of the woman is her descendants and, in the spiritual sense, a special seed coming from Christ that produces the "new birth". Natural enmity exists between natural serpents and man, and spiritually between the ungodly and the "born again" man (John 15:18; Galatians 4:29; 1 John 3:12).
But the significance goes even further: this is the first prophecy of the coming of Christ as the Redeemer who will defeat Satan. Jesus Christ is the seed of the woman generated by the Holy Spirit and not coming from man as Eve (Galatians 4:4; 3:16). The Scripture was fully fulfilled when Christ defeated Satan at the cross (Colossians 2:14-17).
Thus, in the spiritual sphere the curse against Satan was that he would be defeated by Christ, or crushed by the Seed of the woman, and that in this way his dominion over the creation of Adam would be destroyed. Christ crushed the head of the serpent on Calvary, but the final action of Christ in holding Satan and freeing earth of all rebellion is still future. In the second advent of Christ, Satan will be defeated and cast into the bottomless pit for 1,000 years. Then, having been released to deceive the nations for a short time, the Slanderer and enemy of good, which is the Dragon and Old Serpent, will be finally released in the lake of fire forever, with all human and spiritual rebels throughout history (Revelation 19:11 to 20:15; 1 Corinthians 15:24-28).