One day when Jesus entered the temple courts, and while he was teaching, the chief priests and the elders of the people came to him and questioned His authority.  In reply, one of the things Jesus told them was a parable about a man who had two sons:

The a man came to his first son and said, "Son, go and work today in the vineyard."  The son answered and said, "I will, sir!"  But, he lied and did not go!

The man then found his second son and said, "Son, go and work today in the vineyard."  But he answered, "I won't go!"  But afterward he regretted what he had said and went and worked in the vineyard.

Jesus asked the priests, "Which of the two did the will of his father?"   They answered, "The second son."  Jesus then said to them, "I tell you the truth, that tax collectors and other sinners are entering the Kingdom of God before you.

For John the Baptist came to you to show you the way of righteousness, but you did not believe him, but these tax collectors and sinners did.  And even after you saw this, you did not repent and believe John."

Jesus was talking about obeying God from the heart and not just putting on a show that they served God.  Can we do that?  Can you come to Sunday School and pretend that you are a real Christian, and make everybody believe that you are? (Let the children respond).  Yes, you can, but you cannot fool God!  He sees our hearts and knows exactly who we are, and if we are really one of God's children.

Now, the priests and other religious leaders refused to believe that Jesus was the Son of God, and was to be the Saviour of the world.  They were like the first son.  They said that they loved and served God, but they lied and only put a show to all the people in the town.

The second son is like each one of of us.  Why can I say that? (Let the children rspond).  It's because we have all disobeyed God and so fall short of His standards.  We were going our own way, and said "No!" to God, but then we turned to Jesus and asked Him to forgive our sins and become our Saviour.  And now we are obeying God and serving Him with all of our hearts.

Nicodemus, a ruler of the Jews came to Jesus by night, and said to him, "Rabbi, we know You are a teacher who has come from God.  For no one could perform the miraculous signs You are doing if God were not with him."   Jesus then replied, "I tell you the truth, no one can see the kingdom of God unless he is born again."

Jesus then went on to explain that He was the way to Heaven.  In verse 16, Jesus said:

"For God so loved the world that He gave His one and only Son,
that whoever believes in Him shall not perish but have eternal life."

Nicodemus had to understand that God did not send His Son into the world to condemn the world, but to save the world through Jesus (v17).  Jesus then gave Nicodemus the key to Salvation:

"Whoever believes in the Son is not condemned,
but whoever does not believe stands condemned already
because he has not believed in the name of God's one and only Son."

Yes, the key to eternal life is one of obedience and belief.  We need to obey God's Word and believe that Jesus is our Saviour.  Nicodemus did, and so can you!

God bless.