To follow Christ is to learn humility and submission. This isn’t just for one group of people over another. Peter’s point is that we should all learn it in the places where we are: slaves to masters, wives to husbands, husbands to wives, and all of us to the government authorities. This isn’t some hierarchy that Peter lays out so we can see who should be the boss of someone else. The point is those who are learning submission, not requiring special circumstances or some high holy ritual. It can be practiced right where we are.