TEXTUAL SOURCES: 1 PETER 2:9 AND EPHESIANS 2:10
The phrase “Royal priesthood” mentioned above is not just talking about the kingdom of priests but it connote the authority giving to you to act in the name of the king i.e. you are a royalty so you can walk like a king, talk as a king and even dress as a king.
No wonder God said in Genesis 1:26 that “let us made mankind in our image, after our likeness and let them have COMPLETE AUTHORITY over everything on the earth”, He had made you a king from the beginning {the highest of his creation} with complete authority over everything and that show how priceless you are to him {God}. You are created to exude his excellence and showcase his wonderful deeds, display his virtues and perfection and to reign over the earth.
You are a son to HIM and not a slave to SIN, so please behave like one and exercise your assured AUTHORITY in HIM.
He created you so as for you to manifest his Beauty, Holiness, Grace, Glory and excellence and you are the most valuable asset he get but how will you accomplish these when you fail to realized how precious you are to him and have been engaging yourself in thing that didn’t befit you as a royalty [sins]. Remember James 1:19 said, understand my beloved brethren. Let every man be quick to hear, slow to speak, slow to take offense and to get angry vs.20 now said for man’s anger does not promote God kind righteousness. For you as a king who want to manifest all what God has ordained in your hand, you must take note of that 2verses because that is one of the most important attribute of a king {he must be attentive to situations\circumstances around him & be considerate}.
You are a STAR [He also called you a light] and you must strive to behave as one ALWAYS and not to let this sinful nature to quench your light through sins.
Another crucial thing to do as a worthy king is to get rid of all uncleanness, the rampant outgrowth of wickedness and to receive & welcome in humble spirit the maker word and most importantly to be the doer of the word {vs.21-22}.
Even though you might not be Holy or righteous now but there is still a chance for you to recheck your path and get rid of all the unclean things around so that you will be address by him as true son [Heir] and not just any bastard because he is a father, God and lover that gives second chance.
CONCLUSION
You must know that even though you are the salt of the world once you lose your saltiness that signify your end {Mathew 5:13}, I pray that our end will not arrive untimely. You must know your real worth so as to do those good works which God has predestined for you and not to waste all those authorities he has bestowed upon you.