God made all angels and creatures with a free will.
He didn't create evil, He created laws and He created people and angels and creatures to choose to love.
Love is a choice, it's an action, not just a feeling.
Lucifer used to serve God, until the day that he wanted to be worshiped and was cast down from heaven.
God created adam and eve and gave them a law, which was to not eat of the tree of knowledge of good and evil because they would die.
They knew the consequence which was death, but they still did it. Satan only acted as the one who convinced eve because she forgot
about what God had said, she chose to listen to the serpent and chose to eat of the fruit.
In essence, it is adam and eve who brought about all the evil you see here on earth.
They were in charge of all the earth, but the day they ate of the fruit sin entered into the world.
So, final conclusion. God created the possibility to sin, the possibility to choose evil or the possibility to choose good. If you refuse to do wrong, then you love God..