One may take different paths to reach the same goal but what is the common quality one must acquire to be successful?

The Lord does not insist on all men following one path and accepting one discipline. There are many doors to His mansion. The main entrance is, however, moha-kshaya (overcoming attachment). This is what Krishna exhorted Arjuna to achieve. Arjuna lost heart and allowed the bow to slip from his hand because he was overwhelmed by a deluding type of attachment. Krishna had to demonstrate to him that the kinsmen whom he dreaded to kill, teachers whom he wished to live, those whom he loved and hated, all were but instruments of His Will, puppets pulled by His Hand! This destroyed his attachment and he resumed his task, without any attachment to the consequences. That made him the recipient of the greatest lesson in history. This lesson is valuable for the theist as well as the atheist, for both have attachment to the consequences of their tasks, an attachment which will colour their eagerness and double the distress when disappointed.

– Divine Discourse, Mar 28, 1967.