Why did God give us free will knowing our destructive ways?

If you think about it logically, the chances of a deity existing are slim to none. There are too many flaws in religion. If he is omnipotent, why did he create the angels to help him, why did he create Lucifer, knowing he would turn bad. He could easily distribute harsh punishment himself, look at the great flood and the burning of sodom. If he is omniscient than why bother doing anything, you already know the outcome. If he was omniscient he would know that humanity would commit deicide by the 20-21th century. He's as real as you want him to be, you can make him everlasting or kill him in an instant with your mind.