I wasn't a Christian when I first read it.
It also is a good exhortation for the converted in their unending war against evil done under the name of Jesus Christ.
When you read 1 Peter as a lost person what did you see was the message of salvation there drawing lost sinners to perfection? Wake up and arm yourselves against sin?" No. That sounds like a message to born-again Christians.
1 Peter 4:1
Forasmuch then as Christ hath suffered for us in the flesh, arm yourselves likewise with the same mind: for he that hath suffered in the flesh hath ceased from sin;