Why Diabolis (Satan) was created?

In some of the Koranic verses, the creation of Diabolis (Satan) is mentioned:
 

1. Once your Lord told the angels: “I am about to create a human being out of clay. When I have fashioned him and breathed some of My spirit into him, drop down on your knees before him.” The angels all bowed on their knees together except for Diabolis, he was too proud and  a disbeliever besides . He said:” Diabolis, what prevents you from kneeling down before something I have created with My own hands? Have you become too proud, or are you overbearing? He said: “I am better than he is, you created me from fire while you created him from clay.” He said: “clear out of here! You are an outcast, upon you My curse will rest until the Day for Repayment.” He said: “My Lord let me wait until the day when they will be raised up again.” He said: “you are one of those who may wait till a day in known time.” He said: “through your influence. Iii seduce them all except for those among them who are your sincere worshippers.” (38:71-83)
At first Satan was not Satan, ha was converted into Diabolis (first he was angel) Diabolis is not the only factor that deceives man, if there was not Diabolis man would obey his passion only invites man to evil, but it is the man himself  who accepts his invitation and perform evil acts:
2. He has no authority over those and believes and rely their Lord. His authority rests only on those who enlist him as a patron, and who associate others with him. (16:99-100)
3. I have no authority over you except that I appealed to you, and responded to me. Do not blame me but blame yourselves! (14:22)
4. Enticeany of them whom you can with your voice. [God says to Satan] set upon them with your cavalry and manpower .share wealth and children with them, and promise them anything. (Yet Satan merely promises them illusion)
5. He (Diabolis) said: “since you have let wm wander off [ll waylay them along your straight Road. Then I come at them from in front of them and from behind them, on their right and on their left. You will not find that most of them are grateful. (7:16-17)