"So how," you may ask yourself, "does one endure the results of past actions?"
It's all about taking responsibility for our own lives. In our litigious society, we are so quick to blame others for any difficulty that falls on us. We want to blame anyone but ourselves.
Upon encountering difficult times, those who practice the Way take responsibility for their own actions. Realizing that in the past they have forgotten what is essential and pursued what is frivolous, they acknowledge their own misdeeds and recognize the fruit of their actions.
This is not the same as compulsive guilt. The wise recognize both the extent as well as the limits of their own responsibility.
Tossed by currents and waves, committing sins and transgressions, one accumulates misdeeds which bear fruit later in life, even if one is no longer committing transgressions. Although no one can see from where this store of evil karma arises, the wise just accept it without rancor or recrimination.
So upon meeting hardship, don't grieve, just recognize your own responsibility.
When you can do that, the body's suffering can become a gate to enter the Way.