Life presents many ups and downs and it's all about how we handle them. It is natural that when one is going through a rough phase, one gets frustrated and gets attracted towards renunciation of karmas as we are all under the illusionary belief that our karmas as well as those of others bring us happiness or misery. Arjun is also going through this dilemma and wants to renounce the karma of fighting the battle.
Krishna clarifies that he is a sanyasi (renunciant) and yogi who does his bounden duty without depending on the fruits of action (karma-phal); not the one without action (6.1). More explanation about bounden duty is likely to bring more confusion because it's purely experiential. To learn how to swim, one has to dive into the water and similarly, one should face life to understand bounden duty; being joyful without the help of senses being the parameter to measure our progress like floating for swimming.
Similarly, a seed coat is expected to protect the embryo and in the right circumstances, it is also expected to give way to sprout. Though it looks natural to us, from the seed coat's point of view it's confusing- once to protect and later not to. Like in the case of the seed coat, performing a karma bestowed on us by the all powerful present moment, without the burden of the past and the expectations from the future, is the bounden duty.
Secondly, Krishna says that sanyasi is the one who dropped the karma-phal but not karma. This breaks the self fulfilling prophecy of 'no karma means no pain nor sin.' It qualifies each one of us to be a sanyasi without resorting to escapism. Whatever may be the circumstances, one is entitled to the joy of a sanyasi the moment one drops the expectation of fruits of action.
Source - Daily World