In the second half of Parshat Shoftim, the portion deals with several aspects of the nation's conduct when it goes to war. The Torah tells us that a designated Cohen addressed the army before going to battle to encourage the warriors to be brave and not fear the war. The verse continues by telling us that an officer will add to the words of the Cohen and declare, “Who is the man that is afraid and fainthearted? Let him depart and return to his house, so that he might not make his brothers' hearts melt like his heart.”
The Talmud records a dispute between Rabbi Akiva and Rabbi Yossi Hagellili regarding the fearful individual referred to in the verse. Rabbi Akiva understood the fear literally, that the person was afraid of war. For Rabbi Yossi Hagellili, on the other hand, the anxiety was not the traditional fear of battle, but rather related to a person who was a sinner, and thus was cognizant of the fact that he was unworthy of the protection of Hashem.
It is very possible that the dispute between the rabbis came about as a result of different viewpoints on a contemporary issue of the second century. When Bar Kochva rebelled against the oppressing Roman Empire and mobilized a military force, he was backed by very strong support from Rabbi Akiva. For Rabbi Akiva, a Jewish army was not a theoretical concept but rather an issue that was quite relevant. For Rabbi Akiva, fear of battle was "Halacha L'Maase" (a contemporary halachik issue). Therefore the verse was understood by its literal meaning, that when a person is afraid, he cannot be present in the battle field. Rabbi Yossi Hagellili, on the other hand, was not a supporter of the uprising, and therefore viewed a Jewish army as a concept that belongs to the Utopian Messianic era when only the righteous go to battle and the victory will be supernatural. Thus the fear relates to a spiritual condition and not to conventional anxiety.