A Christian is a follower of Christ AND his teachings. It is a new covenant and that makes certain promises to believers and gives some excellent directions on how to live, love and die.
The Old Testament or the old covenant no longer applies to Christians. That was what that whole nailing to the cross thing was about. It does demonstrate one point over and over again. Men are fragile and fallible, always. There is nothing "new" in this world, every possible sin you can imagine and so many more that you can never even begin to imagine have all ready been committed by someone - since well, forever.
Professed Christians dress up to play at church to look good for their community, to network and they sneer at others who do not look, dress or believe as they do. They think nothing of withholding the basics of life to the needy or to children. These “Christians” who most loudly profess to love America and Jesus, have no idea that they are the ones who are wretched, miserable, poor, blind, and naked in the eyes of the God they declare to love.
Relevant Revelation passages below.
The KJV - Revelation 3:14-17
14. And unto the angel of the church of the Laodiceans write; These things saith the Amen, the faithful and true witness, the beginning of the creation of God;
15. I know thy works, that thou art neither cold nor hot: I would thou wert cold or hot.
16. So then because thou art lukewarm, and neither cold nor hot, I will spue thee out of my mouth.
17. Because thou sayest, I am rich, and increased with goods, and have need of nothing; and knowest not that thou art wretched, and miserable, and poor, and blind, and naked: