...who have been chosen
according to the foreknowledge of God the Father,
through the sanctifying work of the Spirit,
for obedience to Jesus Christ and sprinkling by his blood:
Grace and peace be yours in abundance.
There is so much theology in this verse. I could never do the entire thing justice. Consider though a couple of points:
First, notice the combined work of the trinity. We see the Father and the Spirit and the Son all doing this work of Salvation together. Sometimes it is easy to skip over the amazing miracle of the saving of a soul. It is no wonder that the angels rejoice when one soul is restored to fellowship with God.
Notice also that the choosing of God leads directly to our cleansing and our obedience. Salvation means something. There are divine actions associated with your salvation. We cannot see any of these actions, but we can see the results. God's actions will not return fruitless.
One last thing. Notice that there is Grace and Peace in abundance. This is written to those who are scattered throughout. Maybe they are feeling alone. Maybe they are feeling discouraged. Peter gently reminds them that there is Grace and Peace, even for them, but it is not because of their actions, it is to bring Glory to God for His goals and purposes in Salvation.