Rabbeinu Bechaye takes the story of the spies as an opportunity to explain the concept of אין סומכים על הנס, that we are not allowed to rely on miracles.
We are obligated to do our part בדרך הטבע, through natural means. Hashem will then step in and make things happen.
There is another term associated with this idea. This is what is known as השתדלות. This comes from the word, להשתדל, to try. It is a further emphasis on our responsibility to do our part בדרך הטבע, to act within nature.
Rabbeinu Bechaye says that man was created in a natural way, so that we act within nature. Despite all of this, the Jewish people are considered למעלה מן הטבע, above nature. Our very existence defies all logic and the rules of nations. Yet we somehow with Hashem’s help have survived.
In short, we have our responsibility to do our part in nature. And Hashem will do his part above nature.