Throughout this verse, Jesus conveys a message of salvation and God's love. He says that whoever believes in Him shall have eternal life. He did not come to judge the world, but to save it through His sacrifice on the cross. Those who believe in Him receive the gift of forgiveness and the hope of an eternal future with God. He is the source of life and light, and all who come to Him will be saved from the darkness of sin and death.
Since Adam's fall, sin has been imputed to the entire human race. We have all sinned, Jewish and Gentile alike. Each of us has committed sin, fallen short of God's glory, and needs a Savior. Nicodemus, like all of us, had to come to realize that sin must be punished for every sin we commit. We do not have access to the kingdom of heaven until the price of sin is fully paid on our behalf. Eternal life cannot be gained by our own efforts. 
Jesus came to Earth to pay the price for sin and heal the spiritual brokenness of humanity. The sacrifice of Jesus provides eternal life to all who believe in him. God sent His Son to offer grace and salvation to all who trust Him, transferring them from the kingdom of Satan to become children of God and citizens of heaven.

Dear Heavenly Father,  I thank You for the gift of salvation through faith in Your son Jesus. Help me to trust in Him and His sacrifice for my sin. May I have the courage to believe in Him and receive the gift of eternal life. Let me never take for granted the love You have shown me by sending Your only begotten Son to die for me. I pray that I may live a life that honors Your sacrifice and brings glory to Your name.
In Jesus's name I pray. Amen.