The question they had, if the redemption is from Hashem without any intervening help from us or we have to do our hishtadlus.. This question still applies today for our current redemption by starting to build the Bais Hamikdash as advocated in the sefer Aim Habonim Samecha.
Moshe Rabbenu sent the meraglim to realize that they need Hashem’s help to conquer the land of Israel because the enemies are too strong to conquer alone.
What did the Meraglim wrong when they told the truth? Says the Abarbanel amd Maasei Hashem that they were not supposed to publicize their findings.
The Rav Malbim explains the difference between vayosuru and vayraglu. Moshe Rabbenu sent spies to determine the preference of each shevat what land is good for them but they switched their mission to find what is wrong, vayraglu They were suppose to return their findings to the general and not publicize it as indicated by shelach lecha. take ownership of it, explained by Rav Abarbanel and the Maasei Hashem. Even if they told the truth, the emphasis in their report was disparaging by nullifying the preceeded good, leaving at the end a bad taste behind.
It says urei betuv yerusalaim kol yemei chayecha, just see the good of Jerusalem all your life which applies to the whole Israel.