In the spiritual traditions of India, astrology (Jyotish) is always present. In a way it makes sense because what we are seeking is harmony with the universe and the planets mark the rhythms of nature on both the broadest scale and the microscale of our own lives.
The planets are seen as the delivers of karma to us. In a sense our supply of karma is filtered through the planets as seen through our own individual birth chart.
But the flow goes in the other direction as well. As the priests have explained it to me, by performing Navagrah puja or yagya, we are in effecting saying, “Please resolve my karma for me, so I don’t have to suffer.”
Interestingly, the planets themselves once got into big trouble for directly absolving people of their karma, and the major deities got really angry with them, condemned them to wander the earth in the area of south Tamil Nadu called Kumbakonam. After some time they were forgiven and since that time have merely forwarded the request to their boss deities (called atidevata and pratidevata). So from this perspective the Navagraha are simply powerful and necessary intermediaries.