Can satan(or demons) influence our thoughts or feed us negative/blasphemous/discouraging thoughts in our minds?
Short answer is yes.
2 Cor 10:
4 (For the weapons of our warfare are not carnal, but mighty through God to the pulling down of strong holds
5 Casting down imaginations, and every high thing that exalteth itself against the knowledge of God, and bringing into captivity every thought to the obedience of Christ;
(NOTE: IT'S A WAR! We are to examine every thought & discern it's origin)
Luke 4:
1 And Jesus being full of the Holy Ghost returned from Jordan, and was led by the Spirit into the wilderness,
2 Being forty days tempted of the devil. And in those days he did eat nothing: and when they were ended, he afterward hungered.
3 And the devil said unto him, If thou be the Son of God, command this stone that it be made bread.
4 And Jesus answered him, saying, It is written, That man shall not live by bread alone, but by every word of God.
5 And the devil, taking him up into an high mountain, shewed unto him all the kingdoms of the world in a moment of time.
6 And the devil said unto him, All this power will I give thee, and the glory of them: for that is delivered unto me; and to whomsoever I will I give it.
(NOTE: The devil says to Jesus. I WILL GIVE YOU all the kingdoms of this world, THAT WERE DELIVERED/GIVEN TO ME) Also see Matt 4:3-5-6-8-9, 9:34, 12:24-29
Luke 13:16 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?
(NOTE: Satan had the power/authority to physically afflict a daughter of Abraham for 18 yrs)
Acts 26:18 To open their eyes, and to turn them from darkness to light, and from the power of Satan unto God, that they may receive forgiveness of sins, and inheritance among them which are sanctified by faith that is in me.
(NOTE: The RISEN Lord chooses Paul & sends him to Gentiles. To deliver them from the power of Satan)
2 Corinthians 4:4 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.
(NOTE: The god <sm g > satan of this current world system. Used his power to blind minds)
2 Corinthians 12:
7 And lest I should be exalted above measure through the abundance of the revelations, there was given to me a thorn in the flesh, the messenger of Satan to buffet me, lest I should be exalted above measure.
NOTE: Paul teaches Satan had the power to buffet/contend against him)
Eph 1:17-23 Adds context to Ehp 2:1-5
Eph 2:
1 And you hath he quickened, who were dead in trespasses and sins;
(NOTE: Faith in Christ's sin atonement & resurrection, quicken/give us new LIFE)
2 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:
(NOTE: The prince of the power of the air is satan)
3 Among whom also we all had our conversation in times past in the lusts of our flesh, fulfilling the desires of the flesh and of the mind; and were by nature the children of wrath, even as others.
4 But God, who is rich in mercy, for his great love wherewith he loved us,
5 Even when we were dead in sins, hath quickened us together with Christ, (by grace ye are saved
Colossians 1:
12 Giving thanks unto the Father, which hath made us meet to be partakers of the inheritance of the saints in light:
13 Who hath delivered us from the power of darkness, and hath translated us into the kingdom of his dear Son:
(NOTE: Thru faith in Christ we're delivered from darkness/Satan)
14 In whom we have redemption through his blood, even the forgiveness of sins:
Hebrew 2:14 Forasmuch then as the children are partakers of flesh and blood, he also himself likewise took part of the same; that through death he might destroy him that had the power of death, that is, the devil;
(NOTE: Pre-resurrection the devil/satan had/owned the power of death)
1 Corinthians 15:
55 O death, where is thy sting? O grave, where is thy victory?
56 The sting of death is sin; and the strength of sin is the law.
57 But thanks be to God, which giveth us the victory through our Lord Jesus Christ.