Why God doesn't stop satan?

[purplepurpose]

Christians want their God to be caring and loving. If Islam is openly stating that satan works under God to cause suffering to people, or test their loyalty towads Gods holy law and plan, THEN God is evil, if he directs satan to cause so much suffering. It will cause rebellion among conscious and thinking christians. It's is for the reason that Satan is a rebellious and isn't Gods employee, according to so many sermons by christians preachers.

He doesn't work under God. God created him and gave him the choice to either rebel or submit:

Sura 17, The Quran:
https://quran.ksu.edu.sa/index.php?l=en#...rans=en_sh

( 61 )   And [mention] when We said to the angles, "Prostrate to Adam," and they prostrated, except for Satan. He said, "Should I prostrate to one You created from clay?"

( 62 )   [Satan] 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 descendants, except for a few."

Satan was a righteous being once upon a time as it seems to the level of him attending with the angels themselves. But God "tested him" with "Adam's creation". Satan was extremely racist and couldn't handle prostrating to a creature made of clay -Satan is made out of fire-.

He failed his test and chose to go on this eternal crusade against mankind to drag them into hell with him.
God knew he will choose this before he created him, he knows our destinies and our future; that's a corner of faith in Islam's message.

So no, God is "a creator of all things including evil", but he is not evil, actually he wrote mercy upon himself:

Sura 6, The Quran:
https://quran.ksu.edu.sa/index.php?l=en#...rans=en_sh

( 12 )   Say, "To whom belongs whatever is in the heavens and earth?" Say, "To Allah." He has decreed upon Himself mercy. He will surely assemble you for the Day of Resurrection, about which there is no doubt. Those who will lose themselves [that Day] do not believe.

Satan will burn in hell forever? Are non believers will get the same treatment - endless pain? According to Islam.