Be sober, be vigilant; because your adversary the devil, as a roaring lion, walketh about, seeking whom he may devour: Whom resist stedfast in the faith, knowing that the same afflictions are accomplished in your brethren that are in the world. (1 Peter 5:8-9)
A 2003 Gallup poll concluded that 70% of Americans believe in the existence of the Devil. A 2009 Barna survey stated, “A minority of Christians indicated that they believe Satan is real by disagreeing with the statement,” i.e., that Satan is a real entity. I could not find a more recent survey, but my observation tells me that most either do not believe in the existence of the Devil or they are unaware or indifferent of his existence. On the darker side, there is a rise in Satan worship and the occult.
Regardless of survey results or prevailing thought, Satan – the Devil, Lucifer, the Serpent the Dragon, the Accuser – exists. The Bible introduces him first as the conniving serpent in the Garden of Eden (Genesis 3:1). The Book of Job identifies him as the Adversary (Job 1:6; 2:1) – “Satan” means “opponent or adversary.” Isaiah describes his pride and arrogance and his elevated position among God’s angels before his fall (Isaiah 14:12-15). The prophet Ezekiel offers a similar description (Ezekiel 28:11-19).
That the Devil is powerful is clear. However, his power is limited; he is not omnipotent (all-powerful) like God. He is not omniscient; therefore, he has to guess at what God will do. He knows the Bible better than most highly educated theologians do, but he cannot discern God’s ultimate plan; although he realizes his time is growing short.
The Devil is not omnipresent. He is a created being; therefore, he is constrained by time. God’s transcendence allows Him to exist both outside of time and at every point within time (past, present, future) simultaneously. The Devil cannot do that. The Devil must operate in the present, and he can only be in one place at a time. However, who knows how many demons he has working for him! To say, “The Devil made me do it” is probably a false accusation.
The Devil and his angels are immortal; therefore, they know a lot of “history” which is why they can reveal things about people in the past to “psychics.” However, they can only guess at the future.
All that said, the Devil is not to be trifled with. He hates God, and he hates God’s most prized creation – you and me. More than that, he hates God’s people – Christians and Jews – and he wants to do all he can to destroy them. He also thinks he can overthrow God. He thinks that by destroying God’s people, or by attempting to thwart God’s prophetic promises, that he can somehow subvert God. For such an intelligent creature, he really is stupid.
We need not fear the Devil. The Bible assures us that “greater is he that is in you, than he that is in the world” (1 John 4:4). Our leading verse reminds us that we must be “sober.” The Greek word nēphō means to “abstain from wine,” but it implies that we must keep a clear mind. There are many things besides drugs and alcohol that can cloud our thinking – anything that dominates our thoughts at the exclusion of God qualifies as insobriety. We must be “vigilant.” The Greek word there is grēgoreuō, and it means to be “watchful,” to be “on guard.” We are not watchful when the things of this world – things that are insignificant in the light of eternity – constantly and consistently distract us.
The Devil “walks around” (because he is not omnipresent) looking for whom he can devour. Christians cannot be eternally destroyed by the Devil, but he can surely make a mess of our lives if we let him. Therefore, we must be “sober” and “vigilant” and resist him when we remain “stedfast in the faith.” The Devil is a formidable opponent but not unbeatable. “Submit yourselves therefore to God. Resist the devil, and he will flee from you” (James 4:7, emphasis mine).
 “The Devil and the Demographic Details” https://news.gallup.com/poll/7858/devil-demographic-details.aspx
 “Most American Christians Do Not Believe that Satan or the Holy Spirit Exist” https://www.barna.com/research/most-american-christians-do-not-believe-that-satan-or-the-holy-spirit-exist/
 “What the Hell? Satan worship on rise in America” https://www.rt.com/op-ed/357523-what-hell-satan-worship-america/