The Jewish people are called in this parashah by the name Tzivot HaShem - the Army of HaShem, as it is written: "And on this very day that all the army of HaShem left the land of Egypt.".
There are several rules that help make an army strong and successful. Let's talk about three important ones.
The first is to obey.
We all know we should listen to our parents and teachers. However, sometimes we say, "Yes, Mom, I'll do what you ask, but why do I have to?" or "Why do I have to do it the way the teacher told me?".
Soldiers on the front lines don't ask why.
They listen to their commander, who may or may not explain the reason for the order, and they do as they are told. At the end of the battle, there may be time to talk and explain. But while they are in combat, soldiers must obey the orders they receive.
The second important rule is to cooperate.
Every Jew is responsible for one another. In an army, cooperating with one's neighbor means much more than doing something good. It is essential, because it is the only way the army can be successful.
All soldiers in a unit depend on each other.
Soldiers in a tank depend on the driver to take them in the right direction. Paratroopers in the air depend on the pilot to get the plane to the correct altitude and on radar specialists, miles away, to give them the right data.
In the army, soldiers rely on the equipment officer to provide them with the appropriate weapons. Every soldier on the battlefield hopes that their comrades will come to their aid if needed.
The third rule is to understand the importance of each individual.
Even though each soldier knows that the others will help him and be there when he needs them, each must take responsibility for his own position. The future of the entire army sometimes depends on a single guard, or on information passed over by radio by an informant.
Each soldier must do their job in the appropriate manner to ensure the success of the army.
These three rules must also be followed in God's Army.
We follow HaShem's commands without question, we cooperate with our neighbors by showing Ahavat Israel, love for our neighbor, and each one tries to do his job in the least way possible.
Extracted from Please tell me what the Rebbe says.