John Wesley gives a very good commentary on this verse:
"But ye - Who believe in Christ Are - In a higher sense than ever the Jews were. A chosen or elect race, a royal priesthood - "Kings and priests unto God," Rev 1:6. As princes, ye have power with God, and victory over sin, the world, and the devil: as priests, ye are consecrated to God, for offering spiritual sacrifices. Ye Christians are as one holy nation, under Christ your King. A purchased people - Who are his peculiar property. That ye may show forth - By your whole behavior, to all mankind. The virtues - The excellent glory, the mercy, wisdom, and power of him, Christ, who hath called you out of the darkness of ignorance, error, sin, and misery."
A short devotion on this verse gives a deeper understanding of how predestination is contained within it's meaning.
But we may proceed yet farther. Our blessed Savior tells us that there are many mansions in His Father’s house, comparing the house that is to be to that which existed on earth while He yet tabernacled with men. In the temple of the first Jerusalem there was a variety of chambers or mansions, employed for different purposes, though all relating directly or indirectly to the services of the sanctuary. In the new Jerusalem, which will itself be the temple of the universe, there will in like manner be many mansions or chambers. It is very possible that we are not only each of us predestined to heaven, but predestined also each to our particular place in heaven, that our very mansion is fixed. Let the glory which is awaiting us, and to which we are predestined, elevate our characters, ennoble our thoughts, extend our views. Co-heirs we are with Christ Himself, who is our Head; vessels we are designed for high honor; we are of the household of the King of kings; we are a chosen generation, a royal priesthood, a holy nation, a peculiar people, called out of darkness into His marvelous light. W. F. Hook
In this verse, and these commentaries, the Christian is given a clear view of God's intent for them, how noble, how high are His thoughts of us. It is a noble priesthood, and the Christian wears this royal calling as a robe of righteousness. Peculiar, and odd; As Jesus was, so are we, in this world. In it, but not of it.
I can assure you, Satan does not want you to study the bible, because if you did, verses such as these would open your mind and heart, and reveal to you God's great love, and eternal desires for His people. It should move us to be more diligent in our walk, and draw ever closer to Him-who is all love, and a consuming fire.
Lorna Couillard