Nicodemus visited Jesus at night.
You rarely hear these words in connection with Christianity today, "Are you born again?"  You heard this question throughout the 70s, during the great Christian revival in the US, more frequently than you ever hear it today; yet these were the very words Jesus spoke to Nicodemus, who came to Jesus at night to hear what He had to say.  Nevertheless, these words are central to what the word "Christian" really means.   

You might ask yourself why Nicodemus visited Jesus by night, in the "cloak of darkness" you might say, instead of during broad daylight.  I think Jesus's statement to Nicodemus, recorded in John 3:3, was indicative of Nicodemus's state of mind at the time.  Jesus said to him on that occasion, "...truly, truly, I say to you, Except a man be born again, he cannot see the kingdom of God."   

Nicodemus went on to ask Jesus how a man can go back into his mother's womb and be "born again."  At that time, he clearly didn't understand what it meant to be "born again."  Paul explained it well when he wrote to the Corinthians about Christianity, "If a man is in Christ (a follower of Christ), he is a new creature; old things have passed away, behold, all things have become new" 2 Corinthians 5:17.  Now, doesn't that sound just like being "born again?" 

You might also ask yourself, if you are a professed Christian, Am I a "light that is set on a hill (Matthew 5:14)," or, Am I hiding under a cloak of darkness? 

John 19:39 tells us that Nicodemus at first came to Jesus by night, obviously pointing to the fact that once he became truly converted (born again), he was no longer ashamed to be associated with Christ Jesus during the day. 

Why are we, Christians, referred to as a "light that is set on a hill," the "salt of the earth," "witnesses," etc?  We have been called to live separate from the world, as we live in this world, in order to win souls.  If we live no differently than the rest of the world, how can we be the "light" Jesus spoke of?  Jesus said, "You are the salt of the earth, but if the salt has lost its savor, how can it be salted?  It is therefore good for nothing, but to be cast out and trodden under the feet of men" Matthew 5:13.  If Christians don't live as Christ lived, we will have no effect in the world. 

The message here is, Don't call yourself a Christian if you do not emanate the love of Christ.  2 Timothy 2:19 says, "The foundation of God is sure, having this seal: the Lord knows those who are His (disciples).  Let every one who names the name of Christ depart from iniquity."

There isn't much time left to do the work God has placed us here to do, be witnesses - examples to the world.  Will we stand up and walk with Christ like honorable men and women of God, or "hide under the cloak of darkness?"  The Lord knows those who are His.  God bless you.