Message from Allah for you

   Allah Almighty says in Aya (6) of Surat Fatir {Indeed, Satan is an enemy to you, so Take him as an enemy, he only invites his party to be among the companions of the blaze}, Allah warns mankind against Satan's enmity towards them, so Let not Satan deceive and tempt you from believing in Allah and from following His Messenger, for Satan is an enemy to you, and Allah commanded mankind to take him as an enemy, oppose him, and deny what he deceives them with, where he only intends to lead them astray so that they enter the blaze of Hellfire with him, as his mission is to invite his companions to be among the companions of the blaze of Hellfire. 

 Allah has made clear that Satan's enmity towards mankind is ancient, when he declared that he would destroy Adam's progeny except for a few because Allah has honored Adam over him and commanded him to prostrate before Adam, but he claimed that he is better than Adam and refused to prostrate before him and said to Allah {He said Do You see this one whom You have honored above me?, if You delay me until the day of resurrection, I will surely destroy his progeny except for a few, Surat Alisraa, Aya 62}.

 And Allah warns the Children of Adam against Satan's enmity towards their father Adam, saying in Aya (27) of Surat Ala'raf {O Children of Adam! Let not Satan tempt you as he drove out your parents from Paradise, stripping both of them of their clothes to show both of them their private parts, indeed, he sees you, he and his tribe, from where you do not see them, indeed, We have made the devils allies to those who do not believe}. So Let not Satan tempt you from obeying the command of your Lord as he did to your parents, Adam and Eve, when he deceived them and urged them to eat from the forbidden tree, and they obeyed him and disobeyed Allah's command, so he drove them out from Paradise by his deception, stripping both of them of their clothes to show both of them their private parts, so Satan caused both of them to descend from the blessings that they were in to the world of hardships and misery, so Do not follow his footsteps lest you would perish. 

 Then Allah assures that Satan and his descendants see mankind from where they do not see them, so humans cannot see demons in their true form in which Allah created them, except during the time of a Prophet as a sign of his prophethood, like the demon who appeared to Allah's Messenger (PBUH), where as narrated by Abu Hurayrah that Allah's Messenger said: "Last night a demon from the Jinn came to Me, or the Prophet said a similar sentence, to disturb My prayer, but Allah gave Me the power to overcome him, I intended to tie him to one of the pillars of the mosque till the morning so that all of you could see him, but then I remembered the statement of My brother Solomon {And grant Me a kingdom that will not belong to anyone after Me}, the sub narrator Rawh added then He (the Prophet) dismissed him humiliated" (Sahih Albukhari 461), but Allah gave demons the ability to take on others forms, like the demon who appeared to Abu Hurayrah in the form of a man stealing the charity of Fitr (Sahih Albukhari 2311).