God could simply exert raw power and snuff Satan out. That would glorify God’s power. But it would not display so clearly the superior worth of Jesus over Satan. That will be displayed as Christ defeats Satan by His death and then by winning allegiance from the saints because of His superior truth and beauty above the ugliness and lies of Satan.
Piper, J. (2004) Life as a Vapor, 67-68
“How sweet all at once it was for me to be rid of those fruitless joys which I had once feared to lose . . . ! You drove them from me, you who are the true, the sovereign joy. You drove them from me and took their place, you who are sweeter than all pleasure, though not to flesh and blood, you who outshine all light, yet are hidden deeper than any secret in our hearts, you who surpass all honor, though not in the eyes of men who see all honor in themselves. . . . O Lord my God, my Light, my Wealth, and my Salvation.”
John Piper translating Augustine (The Confessions, Book 9)
Semper Reformanda 