Begin by having "Richie" "interrupt you" with news about the Sunday School party. Make sure "Richie" brags about his riches and how he is going to show all the other "poor" kids how rich he is, by what he wears and takes to the party.
"Richie" could say for example: "The other kids in the Sunday School ought to get rich too." Storyteller: "How can they do that?" "Richie":"The same way I did - have a rich father."
A few "Well, just how rich are you?" lines, should proceed the Storyteller's comment that all the other kids in the Sunday School are not rich like he is, and won't they feel bad when he is "showing off".
"In fact, Jesus taught that it was not how rich your were or how good you were that mattered, but rather how "poor" you were. "Blessed are those who are poor in Spirit, for they shall inherit the Kingdom of God". Quote the verse about the Camel and the eye of the needle as well to "Richie".
"Richie" (Obviously a bit scared.) responds by asking if a rich man can even get in. You answer "Yes, but it is very hard." Then proceed to converse with "Richie", telling the story of the Rich Young Ruler:
Point out to "Richie" that it was not the riches that was his problem, but that he loved them more than he loved Jesus. after all he went away sad, because he was very rich.
Explain to "Richie" why it is so hard for someone who is "rich" to enter the Kingdom of God. (The Camel verse). Make a point here that to love anything more than Jesus is wrong. And that some people think they are good enough to enter heaven because of the things they have done - but the Bible says we must go to heaven trusting only in what Jesus has done for us on the cross.
Let "Richie" ask the questions that a child would need to ask to understand what you are saying.
"Richie" concludes he needs to be "poor" too, and asks how.
The Storyteller tells "Richie" about trusting in Jesus and "turning" from everything else.
The Storyteller gives him some suggestions of things that a child might love more than Jesus: his toys, his clothing, his "smarts", his friends, etc. "Richie" balks at each, but finally decides to give all his money to the Sunday School teacher for the poor and the missionaries and be just like the other kids.
"Richie" could conclude by commenting to the Storyteller. "You know, those poor kids in the Sunday School are really very rich. They have Jesus as their father and they get to inherit eternal life."