as Sarah obeyed Abraham, calling him lord, whose children you now are, if you do well, and are not put in fear by any terror.

 Peter is, in effect, saying that in baptism God said to the man coming direct from heathenism: "Do you accept the terms of my service? Do you accept its privileges and promises, and do you undertake its responsibilities and its demands?" And in the act of being baptized the man answered: "Yes." 