Of Jesus’ teaching to Nicodemus that one must be born again (from above) to enter God’s kingdom the following writers comment:

-“How difficult it is for men to take a spiritual view of life, and to understand that the kingdom of God can never be brought in by political expedients and social reforms and natural processes; but that the first great need is a renewal of the heart and a divine transformation of each individual…” (Dr. Charles Erdman)

-“Man’s condition demands that he be born again if he is going to see or enter the kingdom of God.  This is not a popular doctrine.  Most people don’t believe it.  Instead, they believe that if a person does something of merit, he or she will qualify to enter God’s kingdom.  The problem, however, is that all of us are born with an old sin nature, and there is nothing we can do to change it.” (Dr. John G.Mitchell)

-“In our first birth we are ‘born of flesh’ and ‘born of water’; but in our second birth we are ‘born from above [again]’ and ‘born of the Spirit.’  Our first birth leads to death, but our second birth brings eternal life.  The new birth is a new beginning that results in ‘newness of life.’ (Romans 6:4). (Dr. Warren Wiersbe)