Doubt sows the seeds of not trusting G-d and thus we are stopped from pursing G-d with all our heart mind, body, soul, and might. Doubt thus leads to attacks from without and from within and this will stop us from entering into The Promised Land.
Doubt will also stop the Messianic Redemption.
L-rd please remove all doubt from me.
“At the next stop, there was no water to drink, but instead of trusting that G‑d would provide for them, the people complained. G‑d had Moses strike a rock with his staff, and this rock miraculously gave forth enough water for all the people’s needs. This “well” accompanied the Jews throughout their trek through the desert. The Jews were then attacked by the nation of Amalek.
Amalek came and fought against Israel at Refidim. Exodus 17:8
The physical attack of the nation of Amalek was the outer manifestation of the spiritual attack of the people’s inner Amalek – their doubt regarding G‑d’s care and involvement in their lives.
This inner Amalek continues to plague us today, attempting to sow doubt and cool our religious fervor. It acknowledges that G‑d exists, but tries to convince us that G‑d is too great to care about the details of our Jewish observance. Doubt leads to doubt, and eventually our inner Amalek convinces us that G‑d is not involved in human life altogether. That, in turn, causes us to abandon our search for G‑dliness and spirituality.
Thus, just as the Exodus from Egypt reoccurs in every generation and every day, so does the war with Amalek. Every day, we must silence the voice of doubt that seeks to halt our spiritual progress. Once we successfully leave our inner Egypt and overcome our inner Amalek, we are ready to receive the Torah anew and enter our Promised Land.
Successfully implementing this process of spiritual growth on an individual basis will hasten its collective fulfillment, bringing the world to its Messianic Redemption.1 Sichot Kodesh 5739, vol. 2, pp. 144–145; Torah Or 84b–85b; Sefer HaMa’amarim 5747–5751, pp. 101–105.