We must always make positive efforts to nip them in the bud itself or else over a period of time it shall encompass our whole being. Dadashri advises that we must try our best to prevent the glass, which might have slipped from our hands, from hitting the floor. Even after our best efforts if the glass hits the floor and breaks then only we can proclaim it to be 'vyavasthit' - not before that. 'Gnan' is not to be misused in any way. Just don't take solace believing it was 'karmic' account that has got settled. Wherever you feel that these bad habits are creating obstacles in your spiritual progress then those need to be dealt with firmly whereas if things are progressing smoothly on the path of 'Gnan' then there is no need to stop that, in that case one should remain in 'Gnan'. Call it fate or scientific circumstantial evidence only after having given it your best shot.