Leviticus 20.26 observes I have set you apart from the other peoples to be Mine. God created humanity to love Him, to glorify Him and to enjoy Him forever.
Almost immediately humanity chose to worship ourselves rather than worship God resulting in death, emptiness and brokenness. Nevertheless God in His love, grace and mercy has been pursuing humanity in order to reconcile everyone back to Himself.
Those who have been restored to Him are required to live lives pleasing to God proving His wisdom, power and love. This battle within ourselves for allegiance to either God or self is manifest in whom we seek to please.
All humans have a strong need to be accepted, this manifestation becomes most obvious when we are young teenagers. Originally in our design it was to focus on God as we near adulthood to begin our responsibility to serve and worship Him.
In our rebellion this natural tendency has been corrupted so that we seek to please men and ourselves instead of God causing us to compromise and rebel against His will and His ways even to our own or others destruction.
The Christian must understand that through Jesus Christ they have been restored to God, adopted by God and paid for by the blood of God in Jesus Christ. This restoration is to result in a new life lived for the pleasure and glory of God.
No longer are Christians to look like the rest of the world whose desires are self-fulfillment and self-gratification but rather as children of God we are to reflect the character and ways of our Father Who is good, loving, humble and giving.
Christians should be obvious in the world for they are those who reflect the true image of God in service, sacrifice and love for the restoration of the world.