There are two types of people, both performing the same action of locking their door at night, but they are each doing it for a different reason.
One is confident that the lock is strong and will protect him, while the other locks his door with a strong trust in God, Who will protect him.
The first person may be held liable for depending on the physical lock. The other person will be rewarded for his trust and prayers. ~ Eved HaMelech