Nevertheless, he has a problem. Sincerity of belief doesn't make something true, and poor Linus is left in the pumpkin patch again, finally succombing to fatigue, and must be rescued by his sister who, because she has been through this before, sets the alarm for the middle of the night and comes to get him.
It's hard to ignore the irony of this situation. Everyone knows he's wrong. His own sister calls him a "blockhead." But it isn't only because the Great Pumpkin doesn't exist, but because Linus has the Great Pumpkin confused with Santa Claus. Charlie Brown sums up the problem by saying, "we're obviously separated by denominational differences."
Thankfully, we don't really live in a world where truth is so subjective. Yet, there are many today who in effect validate the "Great Pumpkin" approach to belief, particularly as it relates to salvation. The thinking goes something like this: anyone can get to heaven, as long as he is sincere about his belief. But does God really honor sincerity of belief?
The story of Jesus' discussion with the Samaritan woman in John 4 is instructive on this point. After Jesus points out that her statement about not having a husband is true, because she has previously had five husbands, and the man she is living with now is not her husband, she tries to change the subject. She sidesteps his discussion about her husband by bringing up essentially a denominational dispute. "The woman said to him, "Sir, I perceive that you are a prophet. Our fathers worshiped on this mountain, but you say that in Jerusalem is the place where people ought to worship" (John 4:19-20). But Jesus refuses to be drawn into her conflict. Or it could be, as John Piper puts it in Desiring God that the great Soul Hunter "he circled around and is waiting there for her as she brings up the subject of worship?"
In any case, look at Jesus' answer. "The hour is coming, and is now here, when the true worshipers will worship the Father in spirit and truth, . . .God is spirit, and those who worship him must worship in spirit and truth." (John 4:23-24). And here Jesus outlines what is required for true worship. We must worship in spirit (which includes, but is not limited to sincerity), but we must also worship Him in truth. The clear implication here is that if we don't worship Him truly, our worship is not true. Worshiping a vague notion of God is not sufficient (see Paul's address to the men of Athens in Acts 17:22-31).
Now, someone may rightly point out that I started out talking about salvation, and then moved to worship. But the fact of the matter is this: to worship, one must be a follower; to follow God, one must be saved by God (through Christ); to be saved, one must believe; and to believe, one must know Him. Or, as Scripture puts it "But how are they to call on him in whom they have not believed? And how are they to believe in him of whom they have never heard? And how are they to hear without someone preaching?" (Rom 10:13).
Faith is only as good as its object. Faith in the One of supreme value is supremely valuable; faith in a worthless lie is of no value whatsoever.