If we had to find a theme for this week's parsha, it would be the importance and significance of tefillah. The parsha begins with Bnei Yisrael's exodus from Mitzrayim. When the Egyptians realized that Bnei Yisrael had no intentions of returning, they set out in hot pursuit of their former slaves. The Jewish People were terrified, "and Bnei Yisrael cried out to Hashem" (Shemos 14, 10). After all Bnei Yisrael went through, why did Hashem put them in such a terrifying situation?
Rav Wolbe (Shiurei Chumash) cites the Medrash (Shemos Rabba 21, 5) that answers this exact question: "Hashem desired to hear their tefillos. Said Rebbi Yehoshua ben Levi, this can be compared to a king who was travelling and heard a princess call out to him, 'Please save me from these bandits.' The king saved her, and some time later he asked for her hand in marriage. He desired to hear her voice, but she wouldn't comply. What did the king do? He had bandits attack her once again so she would cry out. When the bandits attacked her she began to cry out to the king. The king responded, 'This is exactly what I wanted: to hear your voice!' Similarly, When Bnei Yisrael were subjugated in Mitzrayim, they began lifting their eyes and calling out to Hashem. Hashem saved them with a strong hand and He desired to hear their voice once again, but Bnei Yisrael didn't comply. What did Hashem do? He had Paroh chase after them and they immediately called out to Him. To which Hashem said, 'This is exactly what I wished to hear!" Despite the fact that Hashem has no needs, He "desires" to hear our voice. If we comply, He won't have to resort to extreme tactics to get us to call out to Him.
Rashi on the above pasuk states that when Bnei Yisrael were put through this terrifying ordeal, "they seized the profession of their forefathers" and they began davening. Rav Wolbe explains that Chazal chose to describe tefillah as their "profession," because a person's job is his second nature. A doctor can be awakened in the middle of the night to perform a surgery, and he'll get up and do it without any preparation. So too, when Bnei Yisrael were threatened by Paroh's army chasing them, they immediately began davening. They didn't need any preparation, and they didn't look for other ways out of their predicament; they simply began performing what came to them naturally.
Rav Wolbe related that a student of his told him that during one of the wars he was on a boat with several other Israeli soldiers, most of them secular. They were hit by a torpedo and their boat started sinking, and everyone began calling out, "Hashem help us". What did these secular Israelis know about Hashem? Not much. But all Jews have an innate attachment to tefillah.
At the end of the parsha, Bnei Yisrael were attacked by Amaleik. Moshe ascended the mountain and extended his hands in prayer. "When Moshe raised his hand Bnei Yisrael were stronger and when he lowered his hand Amaleik was stronger" (ibid. 17, 11). Rashi cites the Mishna in Rosh Hashana (29a) which asks how Moshe's hands were the deciding factor in the war. The Mishna explains that when his hands were raised, Bnei Yisrael would look heavenward and subjugated their hearts to Hashem, and He would assist them. Their tefillos were heard and their effectiveness was immediately reflected in the battlefield.
Hashem desires our tefillos, davening is our second nature, and the response is often (although not always) immediate. When Moshe asked Hashem for a Name (i.e. sign) of Hashem to convey to Bnei Yisrael, Hashem responded (see Ramban to Shemos 3, 13) that they need no other sign than the reality that people call out in prayer and Hashem answers them! Do we need any other incentive to turn to Hashem in whatever situation we find ourselves?