One, who has renounced all action through yoga, whose doubts are dispelled through spiritual wisdom, who is self-seated, O Dhananjaya, actions do not bind him.
Krishna is all for ceaseless action. But he says in such active life, the spirit of renunciation should be ingrained. This is ensured by practising yoga, namely the evenness of mind to sukha-duḥkhas and other pairs of opposites, Krishna has emphasized variously.
As for doubts assailing the mind, knowledge about the non-acting and non-involved Self is the full redress.
Understand that in your personality, beyond the ego is the unaffected and uninvolved Self, subtle and all-pervading. That is your real identity.
Where is then any question of such an enlightened one courting bondage at all? That is why Krishna says that no activity, performed as yoga, will bring sin and bondage. Arjuna was a fighter. He had also fought many wars earlier. How will Kurukshetra war make any difference? Arjuna has to be clear in his mind and get rid of all delusion in the matter, says Krishna.