Not everyone who is born again is a "Christian". The first time I said that it surprised the group I was speaking to until they though about it. The word Christian means Christlike. I asked, Do you know anyone who is born again that does not act like Jesus? The answer naturally was yes.
That brings a couple of scriptures to mind:
John 14:15 If ye love me, keep my commandments.
John 13:35 By this shall all men know that ye are my disciples, if ye have love one to another.
We must be careful to be a Godly, Christ like example in all we do. We need to take our witness before others very seriously. Jesus said in Matthew 18:6 But whoso shall offend one of these little ones which believe in me, it were better for him that a millstone were hanged about his neck, and that he were drowned in the depth of the sea.
We are the only example of Christianity that most people will ever see. Most of them expect us to be a phony because they have seen plenty of that in the past. If we will have integrity in all we do, people will be more likely to follow and have an interest in our faith. We need to ask ourselves the question, What would Jesus to do and follow that example all of the time.
Have you ever known anyone who was born again that did not act Christ like? Have you ever acted un Christlike in your dealings with others? If so be quick to repent. Ask the one that you offended for forgiveness. Most people know you are not perfect. They are just looking for you not to be phony.