"When the devil reminds you of your past, remind him of his future."
Wise words. We know where Satan's going. But that leaves our fate unaccounted for. The devil's future may involve his doom, but we still deserve to share in that. And he loves to remind us of that.
So what do we say? Zechariah once had a vision that provides a good example. In it, he sees Joshua standing before the Angel of the Lord, but Satan is also there, bringing up Joshua's unworthiness. But though Joshua was unworthy, the Lord stood steadfast. He swiftly rebuked Satan, saying "Is this not a brand plucked from the fire?" And with that, God removes Joshua's filthy clothes, instead placing clean clothes on him.
This, my brethren, is what Jesus does for us. Our filthy garments, the clothing stained with iniquity, are no longer our problem. These are removed, and God instead clothes us with His own righteousness. Satan has no more ammo against us. Rebuked by God Himself, that devil has no claim on our lives. We are free.