"A royal priesthood": God Himself gave this name to His chosen people when He made the covenant with them at Sinai (Ex 19:6: "You shall be to Me a kingdom of priests").
The force of the expression here lies in the word "priesthood" (cf. note on v. 5), both as applied to the Old Testament people and to the New Testament people.
You will have free access to the throne of God, as priests, to offer sacrifices before Him, to pray, and to bless.
Yet you stand in a special spiritual communion of life with Him who is the King of the whole world. God the Father predestined you to be conformed to the image of His Son (Rom 8:29).
The Son, having ascended into heaven, abides at the right hand of God (1 Pet 3:22). Even according to His humanity, He shares with Him the kingdom over the world.
Therefore this royal authority must be reflected also in you, in your priesthood. Thus it is a royal priesthood (cf. Rev 1:6; Rev 5:10).
Even now, with Christ, you royally conquer the enemies of salvation: the devil, the world, and the flesh. In time, this royal dominion will be revealed still more clearly and splendidly.
Thus what appeared in the Old Testament people only in its beginning must come to full realization and fulfillment in Christians (cf. Isa 61:6; Ps 148:14).
"A holy nation": this too is the name of the Old Testament people, given to them by God (Ex 19:6; Deut 7:6).
As Israel alone among the pagan nations was dedicated to God, and in this sense was a holy nation, or one that was to be holy, so in a still higher sense Christians are, or must be, a holy nation amid the sinful world.
They have been cleansed by the blood of Christ and sanctified by the Holy Spirit (1 Pet 1:2).
"A people taken for a possession": so God calls the Hebrew people, as a people chosen by Him from all the nations of the world for special and higher purposes (Ex 19:5; Deut 7:6; cf. Isa 43:21; Mal 3:17; Tit 2:14).
As those redeemed by the blood of the Son of God, Christians are in a still higher sense than the Jews a people taken by God for His possession, or His special property. They are His own, belonging to Him.
"For all are God's creation, but God's possession consists only of those who have been deemed worthy of this through virtue" (Theophylact).
"That you may proclaim," and so forth: the purpose of this special election of Christians by God as His possession consists in their proclaiming His perfections.
To proclaim means to reveal outwardly what is hidden within, and to make it known to all.
The perfections of Him who called them, that is, God the Father (cf. 1 Pet 5:10), are those divine attributes which were especially manifested in the calling of men into the Kingdom of Christ.
These are especially God's love for man, by which He was pleased to send His Son into the world, and His wisdom and omnipotence. These found the means and removed every obstacle to the restoration of fallen man.
The other perfections of God were likewise revealed in the redemption of the human race.
To proclaim these perfections is the same as to glorify God. This glorification is accomplished by believers both in word and in deeds, not only before fellow believers, but also before the whole world, to stir others also to glorification (cf. Mt 5:16).
God is here called the One who called Christians out of darkness into His marvelous light. This calling is the realization in time of God's pre-eternal election and foreknowledge (cf. 1 Pet 1:1-2) with respect to those predestined to salvation.
It is ordinarily accomplished through the preaching of the Gospel, by the power and action of the Holy Spirit upon the heart. He awakens and increases faith in the Gospel, or in Christ Jesus preached in the Gospel.
This calling to Christ is presented here under the image of a calling from darkness into light (cf. note on Mt 4:16; Jn 1:4-5).
Darkness and light are not literal expressions here, but figurative. Darkness, or the kingdom of darkness, is that sorrowful state in which all people were and are outside Christ's Kingdom, or the Church.
This is true with respect to knowledge and worship of God, and also with respect to the intellectual and moral state. It is the kingdom of Satan, the kingdom of gloom and of every evil and corruption.
Before Christ, and outside Christ, paganism was especially in such a condition. Yet this image is also applied to the Jews (Ps 106:10; Isa 9:2; Mt 4:16; Jn 1:5).
This means that the darkness extended also to the Jews, though not to the same degree, for they had a lamp, the revelation of God through the Law and the Prophets.
To this darkness is opposed the marvelous light of God. Being Himself light in His essence, God takes those who believe in Christ out of this kingdom of religious and moral darkness.
He sets them in His light, in communion with Himself as light. Thereby the mind of the believer is enlightened by the truth of the knowledge of God, the will is sanctified, the conscience is pacified, and the whole person is enlightened.
This light is called marvelous in its origin, its essence, and its effects. It makes sinners, alienated from God, into righteous men and sons of God.
The image in this comparison may be taken from the passage out of the darkness of night into the light of day.