“But you are a chosen race, a royal priesthood, a holy nation, a people for God’s own possession, that you may proclaim the excellencies of Him who has called you out of darkness into His marvelous light; for you once were not a people, but now you are the people of God; you had not received mercy, but now you have received mercy.”
1 Peter 2:9-10

In 1 Peter 2:9, Peter uses a series of terms to describe what believers in Christ become. They become (in the corporate sense) a chosen race, a royal priesthood, a holy nation and a people for God’s own possession.

Each of these terms is taken from an Old Testament passage: A chosen race (Isaiah 43:20), a royal priesthood (Exodus 19:6), a holy nation (Exodus 19:6), and a people for God’s own possession (Exodus 19:5).

But notice that Peter introduces the purpose for these marvelous changes with the word “that.” God has done this marvelous work in order that believers proclaim the excellencies (or praises) of God. The word “proclaim” means to announce, publicize, or tell abroad. Peter then lists three reasons why believers are to announce the excellencies of God.

First, believers are to announce the excellencies of God because it is God who has called them “out of darkness into His marvelous light.” The word “darkness” refers to the believer’s condition before coming to Christ. People who are apart from God live in darkness and are under the control of the prince of darkness (see Ephesians 2:1-3 and 1 John 5:19). When a person enters into a right relationship with God through Jesus Christ, he is transferred from darkness to light (see Acts 26:18). Psalm 107:2 says, “Let the redeemed of the Lord say so, Whom He has redeemed from the hand of the adversary.”

Second, believers are to announce the excellencies of God because God has changed their status. Prior to coming to Christ, they were “not a people.” Apart from Christ men are “like sheep without a shepherd” (see Matthew 9:36). When an individual comes to Christ however, his status is changed from not belonging to belonging to the family of God.

Third, believers are to announce the excellencies of God because they have personally experienced His mercy. Prior to coming to Christ they “had not received mercy”, but on the day that they responded in faith to the claims of the gospel, they “received mercy”. The term “received mercy” refers specifically to the time of an individual’s conversion, to the moment when that individual placed his/her faith in Christ and was transferred from darkness to light and became a part of the family of God.