There are natural laws for farming and other mundane events. These translate to spiritual laws for man . The Bible is a simple book. People think they have to be Biblical scholars to understand it. Nothing is further from the truth. The Bible was meant for the common man, not the intellectual. In our day and age, people are not used to using their minds. They want instant gratification. The Bible takes study, but it is not difficult, per se.
Many spiritual laws are simple. What you sow, you reap, is simple. If you are in a depression and the last thing you want to do is care about another person, force yourself. That is what is called planting a seed. If you plant seeds, when you are down, people will water you. Spiritual laws never fail. They cannot. They are as exact as physical laws such as gravity.