Navkar Mantra is the most important prayer in Jainism.
When we say the Navkar Mantra, we are paying our respect to the Arihant Bhagwans, the Siddha Bhagwans, the Acharyas, the Upadhyayas, the Monks, and the Nuns*. Arihant Bhagwans are in their last life and they have destroyed the four ghati (heavy) karmas which affect the condition of the soul. They have infinite knowledge and don’t have any attachment to anything. They don’t hate anything either. They will get rid of the other four karmas called aghati (lighter) karmas before they die. Then they will become Siddha Bhagwans. They are first in the Navkar Mantra, even though their souls aren’t free because they show us the path to freedom. Since they are our teachers, we pay respect to them first. Those souls who don’t have any karmas and don’t have to go through the cycle of birth and death anymore are called Siddha Bhagwans. Next we pay respect to Acharyas. They are the heads of all monks and live a very pure and perfect life. Then we pay respect to Upadhyayas. They have learned the sacred scriptures and are now teaching them to the monks and nuns. Last we pay respect all the monks and nuns who have accepted to live under strict code of conduct.
We should always recite the Navkar Mantra to pay homage to these great souls. This leads to purer thoughts which in turn leads to purer activities. It should recite it when we wake up in the morning and at the night or for that matter at anytime.