The devil is real and is a threat to saved and to unsaved people alike. Not 
everyone is a spiritual threat to Satan and his earthly domain, but he is still the enemy to all people.
Sometimes it is not Satan that is intervening in one’s life but the devils, Satan’s imps, that also attempt to hamper the works of God and Earth’s people. However, most of the time we get into sin all by ourselves without any intervention from Satan or the “devils.” It is often our own sinful flesh that sins without any supernatural involvement.
There is no Scripture that indicates that Satan can make a saved person lose his salvation and send him to Hell, but the enemy of God and His people can make lives miserable and ruin any testimony one may have for the Lord Jesus Christ. This world is unfortunately full of saved people that fell for the enemy’s tricks and are no longer good Christian examples. Their tarnished testimony leaves a bad taste in many mouths for the cause of Christ because of their lack of resistance to temptations.
Although some would like to blame Satan’s interference for every bad event that happens in their lives, he is not responsible for all the trauma and trials. Here is some of what the Bible tells us about what Satan can and has done to different people, both the righteous and the unrighteous, in the biblical past:
He can take the Word out of hearts and minds, which can keep one from being saved.
“Those by the way side are they that hear; then cometh the devil, and taketh away the word out of their hearts, lest they should believe and be saved.” Luke 8:12
“When any one heareth the word of the kingdom, and understandeth it not, then cometh the wicked one, and catcheth away that which was sown in his heart. This is he which received seed by the way side.” Mat. 13:19
He can blind unbelievers from seeing the truth.
“But if our gospel be hid, it is hid to them that are lost: 4 In whom the god of this world hath blinded the minds of them which believe not, lest the light of the glorious gospel of Christ, who is the image of God, should shine unto them.” II Cor. 4:3-4
He can tempt you, as he did God’s only son, Jesus, while He was in the wilderness.
“Then was Jesus led up of the Spirit into the wilderness to be tempted of the devil ….” Mat. 4:1-10
“And supper being ended, the devil having now put into the heart of Judas Iscariot, Simon’s son, to betray him;” John 13:2
He can be used to test you, with God’s permission, as he did Job.
“And the LORD said unto Satan, Behold, all that he hath is in thy power; only upon himself put not forth thine hand. So Satan went forth from the presence of the LORD.” Job 1:12
He can fight against the saved.
“For we wrestle not against flesh and blood, but against principalities, against powers, against the rulers of the darkness of this world, against spiritual wickedness in high places.” Eph. 6:12
He can tempt us to disobey God.
“And the serpent said unto the woman, Ye shall not surely die: 5 For God doth know that in the day ye eat thereof, then your eyes shall be opened, and ye shall be as gods, knowing good and evil.” Gen. 3:4-5 Satan tempted Eve to disobey Gods commandments.
“And Satan stood up against Israel, and provoked David to number Israel.” I Chron. 21:1
“Wherein in time past ye walked according to the course of this world, according to the prince of the power of the air, the spirit that now worketh in the children of disobedience:” Ephesians 2:2
“But he [Jesus] turned, and said unto Peter, Get thee behind me, Satan: thou art an offence unto me: for thou savourest not the things that be of God, but those that be of men.” Mat. 16:23 Peter was not possessed by Satan. At a spiritually weak point in Peter’s life, Peter was obeying the temptations of Satan rather than the Spirit of God.
He can oppose and hinder God’s people.
“And he shewed me Joshua the high priest standing before the angel of the LORD, and Satan standing at his right hand to resist him. 2 And the LORD said unto Satan, The LORD rebuke thee, O Satan; even the LORD that hath chosen Jerusalem rebuke thee: is not this a brand plucked out of the fire?” Zech. 3:1
“Wherefore we would have come unto you, even I Paul, once and again; but Satan hindered us.” I Thes. 2:18
He can encourage doubt and tell lies against believers.
“Then Satan answered the LORD, and said, Doth Job fear God for nought? 10 Hast not thou made an hedge about him, and about his house, and about all that he hath on every side? thou hast blessed the work of his hands, and his substance is increased in the land. 11 But put forth thine hand now, and touch all that he hath, and he will curse thee to thy face.” Job 1:9-11
He can bring about disease, with God’s permission.
“So went Satan forth from the presence of the LORD, and smote Job with sore boils from the sole of his foot unto his crown.” Job 2:7
He, and the “devils,” can be allowed to hurt one’s body.
“And as he was yet a coming, the devil threw him down, and tare him. And Jesus rebuked the unclean spirit, and healed the child, and delivered him again to his father.” Luke 9:42
“And ought not this woman, being a daughter of Abraham, whom Satan hath bound, lo, these eighteen years, be loosed from this bond on the sabbath day?” Luke 13:16
“And when he [Jesus] went forth to land, there met him out of the city a certain man, which had devils long time, and ware no clothes, neither abode in any house, but in the tombs. 28 When he saw Jesus, he cried out, and fell down before him, and with a loud voice said, What have I to do with thee, Jesus, thou Son of God most high? I beseech thee, torment me not.” Luke 8:27-28
He will lie.
“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.” John 8:44
He can cause trials in our lives, destroy lives, and testimonies.
“Fear none of those things which thou shalt suffer: behold, the devil shall cast some of you into prison, that ye may be tried; and ye shall have tribulation ten days: be thou faithful unto death, and I will give thee a crown of life.” Rev. 2:10
He can control an unsaved person.
“And, lo, a spirit taketh him, and he suddenly crieth out; and it teareth him that he foameth again, and bruising him hardly departeth from him.” Luke 9:39 All demon possessed people in the Bible were unsaved.
As dangerous and hateful as Satan and the devils are to God’s people, Christians have nothing to fear. If we are saved, and close to Him, we will have God’s protection. The danger, however, is present when we stray out of God’s fellowship by being involved in sin.
Trust Christ as your Saviour. Read His word faithfully, and obey all that God shows you (Eph. 2:2), and He will protect you from sin and the enemy’s wiles.
“My Father, which gave them me, is greater than all; and no man is able to pluck them out of my Father’s hand.” Joh 10:29
“Ye are of God, little children, and have overcome them: because greater is he that is in you, than he that is in the world.” I John 4:4
“For whatsoever is born of God overcometh the world: and this is the victory that overcometh the world, even our faith.” I John 5:4
Know your enemy!
Thanks Bro Brinkworth.