And yet Peter's place in the Kingdom is not only certain, but his status as an apostle is going to be celebrated on one of the gates of the New Jerusalem. How does a fumbler and a man of such silly capacity become one of God's precious vessels?
Now the devil has many devices, which we are not ignorant of. If he knows we've memorized all the scriptures about God's promise of forgiveness, and we objectively know our sin is no match for his saving grace, he will try another tack: "You're too silly!"
I bought this one recently. But it took some time walking alone and meditating on Scripture to get the needed spiritual chiropractic. "Nothing can separate us from his love" (From Romans 8:37-end of chapter)