Answer
Happiness and distress certainly arise according to past karma, but the crucial difference lies in how one responds to them.
Consider the example of money.
If money comes into your possession because of previous actions, you are not responsible for the fact that it arrived. But how you spend it determines future consequences.
Similarly, when happiness comes due to past karma, it may simply be the exhaustion of previous karmic reactions. However, a non-devotee generally becomes attached to that happiness and acts in ways that create new karma.
A devotee, on the other hand, has a different goal: Krishna consciousness.
When happiness comes, he accepts it as Krishna’s arrangement and does not become deeply attached. Therefore, much of that karmic result simply comes and goes without generating further bondage.
The same principle applies to suffering.
When suffering comes to a non-devotee, he usually reacts with new material desires, fears, and actions, thereby creating further karma. This becomes a vicious cycle.
When suffering comes to a devotee, he responds through devotional service, remembrance of Krishna, and guidance from Guru and Krishna.
As a result, suffering does not create additional bondage; it can actually become an opportunity for purification and deeper surrender.
Material life revolves around dharma, artha, kama, and moksha. Artha (economic development) and kama (sense enjoyment) are not condemned, but they must be guided by dharma.
For example, sexual life within dharmic principles does not produce the same karmic reactions as illicit indulgence.
The devotee gradually transcends even these concerns because his actions are performed for the pleasure of Guru and Krishna, not for selfish enjoyment.
Therefore, while past karma may still produce temporary happiness and distress, devotional service prevents the creation of new bondage.
The non-devotee continually creates new karma through attachment and aversion.
The devotee allows past karma to become exhausted while engaging in Krishna’s service.
When all karmic reactions are finished and no new karma is created, there is no need for another material body.
That is why devotional service is said to bring an end to the cycle of birth and death.