The determination of God the Father to choose particular persons received expression in the change the Holy Spirit worked in these persons. The term translated as sanctification
describes the concept of being made holy, set apart, being made different from what they were and different from others. The result is that they become strangers, exiles, people who no longer fit in their community. Peter insists that this change is not the result of natural forces (say, economical or sociological), but is the work of the Holy Spirit. The same Spirit who propelled Peter to preach (Acts 2:4; Acts 4:8; 1 Peter 1:12) also changed his hearers so that their lives would now be dedicated to God.
2 according to the foreknowledge of God the Father, in the sanctification of the Spirit, for obedience to Jesus Christ and for sprinkling with his blood:May grace and peace be multiplied to you.