When the Jew Must Fight

Just before Jews made their way into the ocean, with Pharaoh and his army of chariots in hot pursuit, God told Moshe to tell the Jews there was no need doing battle with the Egyptians because God will do the fighting for them. (Ex.14:14)

Four weeks later, when Amalek pounced on the Jews, Moshe tells his people "Go out and fight Amalek!" (Ex.17:9)

Why should Jews sometimes let God do the fighting for them, while other times Jews must put up a fight?

Depends on the enemy's agenda. Egyptians wanted to take the Jews back to slavery. Amalek, on the other hand, sought to prevent Jews from their association with Torah.

Whenever a Jew confronts that which would prevent him from learning Torah, he must fight off this enemy!