What is the main motivation for Hindes to follow the beliefs of their religion correctly

The motivation behind Hindus following their religion correctly is the belief that their good deeds in this birth would be awarded in the next birth.

Explanation:

The teachings of the Hindu religion speak about the idea of reincarnation and that the punishment or reward for the good and bad deeds respectively would be bestowed upon them in the next birth. This ultimately motivates the people following the religion to do good in this birth. It is out of both, the fear of punishment in the next birth and also the will to do good.