Satan is our enemy as Allaah mentions many times in the Qur'an. And he will get the worst punishment in the hereafter. He is one of those who turned away from the obedience of Allaah out of arrogance, and he has lead many astray by making them have false hopes [he cant force no-one, but anyone can try to make someones desires seem better than what they really are, its like someone robbing from a bank, they know they can be punished for it but the desire of money makes them still want to do that sin/crime. - " a wolf in a sheep's clothing " thats what the bad deeds are.]
Everything that happens is by the will of Allaah, yet we still have a freedom of choice. Allaah may have created a situation in our life, and we might have two options, we could either take the right/good option or go down the wrong one [because Allaah has given us freedom of choice.] If we go down the good path, Allaah will bring through more good for us. If satan tries persuading us to do bad, we can either resist it or go along with it - which then leads to us doing sin.
If we do the good, we can get rewarded upto 10 times or upto 700 or more. If we were thinking of doing bad, but we turned away for the sake of Allaah - a good deed will be recorded for us. And if we got persuaded and fell into the sin, a bad deed is recorded for us. But if we repent, this bad deed will be wiped out and replaced with good.