Now there was a day when the sons of God came to present themselves before the Lord, and Satan also came among them. The Lord said to Satan, “From where have you come?” Satan answered the Lord and said, “From going to and fro on the earth, and from walking up and down on it.”
Satan and God are not fighting some kind of “cosmic battle” because there is no contest. He and his fallen angels with him only have as much power and ability which is granted to them by the Lord himself. Don’t misunderstand, Satan is powerful, but God is infinitely more. Take the devil seriously, but understand who you are with the Holy Spirit (if you’re a Believer). Satan is on a leash, he is not free to deceive whomever he wishes. Resist him, and he flees.