Parshas Shlach: Rav Yehonasan Eibushitz - Kalev Had Credibility With The People, Yehoshua Did Not
Rav Yehonasan Eibushitz says that while Kalev took an active role in standing up to the Meraglim, Yehoshua was scared to take a public stand against them. In last week's Parasha, Eldad and Meidad stood in the camp proclaiming their Nevua that Moshe would die and Yehoshua would lead Bnei Yisroel into Eretz Yisroel. Therefore Yehoshua felt he had no credibility to rally on behalf of going to Eretz Yisroel since this was in his interest as future leader.
Why then did Moshe send him? Explains Rav Yehonasan, that Yehoshua was known as Hoshea and not Yehoshua. Only right before the meraglim left for Eretz Yisroel did Moshe privately change his name. Moshe therefore thought that nobody would know that Hoshea was the Yehoshua who was the subject of Eldad and Meidad's nevua. Nevertheless Yehoshua was afraid that Bnei Yisroel would realize that he was Yehoshua and therefore he remained silent.