One of the biggest problems with this week's parasha is that it perfectly demonstrates irrational beliefs in people who have aboslutely no reason for them.
To wit: Having witnessed the ten plagues in Egypt, the splitting of the sea, the giving of the Torah and the appearance of the Shechinah over the Mishkan, the B'nai Yisrael, when confronted with the possibilty of opposition to their entry into their new land, shy away from confrontation and attempt to return to Egypt. This makes absolutely no sense!
However, a careful reading of the previous chapters from the time B'nai Yisrael left Har Sinai until now shows a strange consistency. In all cases where difficulties arose (Kivros HaTa'avah, Tav'eirah) it was all due to one recurring factor: a lack of trust in God's ability. But how is this possible? These people witnessed his omnipotence repeatedly since His first appearance in Egypt. How could they now suddenly lack faith in Him?
One possible answer is to look at how the relationship between God and B'nai Yisrael would change once the Jews began their conquest of Eretz Yisrael. In the desert, B'nai Yisrael lived a miraculous existence, shielded by the ananei hakavod, fed by the water from Miriam's well and by the man, with God's presence shining above them from about the Mishkan.
However, once they entered Eretz Yisrael they knew that the situation would change. All the laws they had learned about in theory, like agricultural rules, work rules and those relating to the Temple, would suddenly come into practice. What's more, they would be spread out across a much larger area without God's presence being obvious in their life. It's easy to believe in God when tangible evidence of His being is available, much harder to keep Him constantly in mind when He's hidden.
Perhaps this is where the understanding of B'nai Yisrael went wrong. The purpose of living a positive Jewish life is to do so in the absence of God's obvious presence. After all, the most important gift He has given us is to exercise our free will, something one cannot do if God's existence is an obvious fact instead of an act of faith. Transitioning from reliance on the obvious to reliance on faith may have been a difficult task for our ancestors and this stumble culminated in the debacle of the spies. It could be that they believed that once God brought them to the border of Eretz Yisrael they would be on their own and that without Him being obviously amongst them they would not have any assistance. The conquest of the Land would be up to them and they felt they were woefully unprepared for this.
However, this is a lesson for us today. The fact that God is silent, in a state of hester panim as it were, in no way diminishes His omnipotence or omnipresence. He is still HaMakom. It is up to us to reflect silently to feel His presence in our lives and not despair that we are all alone in an uncaring universe. If we strive to fulfill His will, then we will see success just as our ancestors might have had they understood this.