What did Jesus mean by the kernel of wheat that must fall into the ground and die?
Jesus meant His own death, burial, and resurrection. The kernel of wheat illustrates that unless He fell into the ground and died, He would abide alone; but by dying He would bring forth much fruit. He spoke this when the hour of His death, burial, and resurrection was coming.
Les explains that when the Greeks wanted to see Jesus, He did not tell Andrew and Philip to bring them in. Instead He told them to go tell those Greeks that the hour cometh, speaking of His death, burial, and resurrection. Unless a kernel of wheat falls into the ground and dies, it abideth alone; but if it dies, it bringeth forth much fruit. This fits the context's change in format, where Saul is later described as a chosen vessel to bear Jesus' name before the Gentiles.
And Jesus answered them, saying, The hour is come, that the Son of man should be glorified.
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