It's a bit more complex - the evil angels burningly desire to create havoc against God, but cannot execute upon their wishes (or as they understand their own wishes -- they are in denial that they can't actually upset God's ultimate plan) unless God grants permission. They are, so to speak, bound in chains by God. Case in point is Satan and Job. Satan badmouthed Job to God, proposed a plan of action by which Satan would "prove" that his slander about Job was right, and God granted permission, and Satan sprang into action. The upshot is that if you call upon God to carry out a curse but your heart is not right with Him, and even more so if your mind is explicitly upon the evil angel, then this complex of events "may" take place. If God allows.