"Nobody mentioning that the pieces wouldn't fit
You can rearrange them all you want
But the puzzle it was rigged"
He's suggesting that knowing what happens after death is impossible because of the permanent nature of death. The puzzle of what happens to our "souls" is hence rigged, because it is an impossible puzzle to solve.
Another lyric that lead me to this conclusion:
"But I heard someone say they knew that someday that everything would fall into its place
And everything would be fine
And I really truly honestly without a doubt want to believe that everything will be alright"
He says that he wants to believe, not that he does or that he can. In contrast to the lyric just before that statement, It seems that he's reluctantly rejecting that idea.
I think it's about agnosticism and skepticism.
Consider the following lyric.
"Nobody mentioning that the pieces wouldn't fit You can rearrange them all you want But the puzzle it was rigged"
He's suggesting that knowing what happens after death is impossible because of the permanent nature of death. The puzzle of what happens to our "souls" is hence rigged, because it is an impossible puzzle to solve.
Another lyric that lead me to this conclusion:
"But I heard someone say they knew that someday that everything would fall into its place And everything would be fine And I really truly honestly without a doubt want to believe that everything will be alright"
He says that he wants to believe, not that he does or that he can. In contrast to the lyric just before that statement, It seems that he's reluctantly rejecting that idea.