What is the most important quality we must cultivate whether we practice any other spiritual discipline or not?
It is mentioned that "Success begets success." But how is success to be achieved and what is the success you should aim at? The Bhagavad Gita declares: Shraddhavan Labhathe Jnanam (The persevering seeker secures wisdom). This means that without perseverance and earnestness, no success can be achieved. Man is not able to make significant progress towards the Divine because of absence of strenuous striving in the spiritual sphere. Without spiritual practice, reading religious books and listening to spiritual discourses have no value. Study of scriptures and reciting God's names may be good acts in themselves. But, if there is no love, which is the basis of all sadhana (spiritual discipline), they are of no use.