Humans are not demonic forces, but demons and demonic forces can influence humans, oppressing or possessing them. Jesus cast demons out of many people, most notably the Gadarene Demoniac.
Here are some references to supernatural activity impacting people:
Eph 2:1-3 You were made alive when you were dead in transgressions and sins, (2) in which you once walked according to the course of this world, according to the prince of the power of the air, the spirit who now works in the children of disobedience; (3) among whom we also all once lived in the lusts of our flesh, doing the desires of the flesh and of the mind, and were by nature children of wrath, even as the rest.
2Co 4:3-4 But also if our gospel is hidden, it is hidden to those being lost, (4) in whom the god of this world has blinded the minds of the unbelieving ones, so that the light of the glorious gospel of Christ (who is the image of God) should not dawn on them.
2Co 12:6-10 Even if I wanted to boast, I would not be a fool, because I would be speaking the truth. But I refrain, so no one will credit me with more than he sees in me or hears from me, (7) or because of these surpassingly great revelations. So to keep me from becoming conceited, I was given a thorn in my flesh, a messenger of Satan, to torment me. (8) Three times I pleaded with the Lord to take it away from me. (9) But He said to me, “My grace is sufficient for you, for My power is perfected in weakness.” Therefore I will boast all the more gladly in my weaknesses, so that the power of Christ may rest on me. (10) That is why, for the sake of Christ, I delight in weaknesses, in insults, in hardships, in persecutions, in difficulties. For when I am weak, then I am strong.