"For thou art a holy people unto the LORD thy God, and the LORD hath chosen thee to be a peculiar people unto Himself, above all the nations that are upon the earth." (Deuteronomy 14:2)
This was the position of the Israelties. And it happens to be the position of all Christians as well.
God has designated that His people be a holy people...a chosen people...and a special treasure unto Himself. They are separate and set apart for Him...devoted to His worship and service...designed for His praise...chosen to practice His will on this earth...and governed by His holy law. Because of this, they must carry themselves as becomes His children. They must do nothing to disgrace His honor. They must behave in a "peculiar" manner - different from all other people.
With these privileges comes great responsibility.
As God's special treasure, are you conducting yourself as someone who is set apart for His worship and service?