God doesn't like this of course and He will punish Satan at the end for His wicked deeds but God also wishes to test man's ability to resist Satan's lies.
Why does GOD feel a NEED to test HUMANS, that doesn't make any sense, is GOD a SADIST?. If I genetically engineered an animal, then beat it with a stick just to see how it reacted and then punished it when it showed obvious behavioural issues as the result of the trauma, people would describe me as EVIL, not as GOOD. Why do people let GOD of the hook when he is such an overt arsehole?