Soul's Mission
Working in the realm of reincarnation-based therapy, I believe we elect to be born at a specific time that is astrologically chosen for the lessons we plan to learn on earth. Those lessons are vital for us to realize, in our efforts to understand who we are and what we are doing here.
A soul chooses to be born at a specific time that is astrologically calculated for its planned mission on the earth. Astrology helps one find clues as to why one chooses that time and for what potential reasons.
There are many therapists, astrologers, and other like-minded practitioners over the years, who have understood the complimentary relationship past-life regression and astrology hold for each other. They see astrology as a way of helping to identify current carryover problems based on past-life karma. They also view past-life regression therapy as a way of purging these blocks and conflicts. The connection seems to be in the unique knowledge both these methods hold, that intricately work together to support this understanding.
How does astrology help to reveal the souls path?
At birth, we arrive with a purpose and power to master and manifest in the present life, as opposed to coming in the physical reality casually, and hoping for the best. The natal chart shows the plan of life we are here to work on. From the astrological point of view, we can also see the reasons why a particular person will have chosen this path rather than another. The present life scheme is part of a larger one, which seems to include several lifetimes. I call it the "larger plan of the Soul".
On the path of self realization, we come back in human form many times and the Soul seems to specialize on specific themes (larger plans)until complete mastery is acquired, and then will branch out in a new direction for another long term plan. For instance, one will find her-himself on the path of the artist for several lifetimes. When the mastery of this path is achieved, the individual delivers a masterpiece or legacies if you will, and will start a brand new long-term plan in the following lifetime, until all parts of the individual self are fully bloomed.
Other examples of larger plans would be the path of the religious, the path of the magician, the path of the warrior, the path of ruler, etc. As one moves into a new long-term plan, what was acquired before remains hidden in order to allow a better focus on the new master plan.
In the end, all that has been learned, returns fully. The storage of past masteries remains available at any time if the individual needs them in an emergency. We see that sometimes when one will spontaneously know how to handle a sudden and difficult situation without a conscious knowledge of it. This is a past-life memory returning because it is needed.
In the natal chart, we have a pretty good idea of where this person is at in the particular larger plan they are on (just beginning, middle, finishing) and what the nature of the most important difficulty or resistance is. It is known that when we die, ones life will flash in front of our eyes. This allows the immortal spirit to review how we made out with the original plan. When the work is done, it becomes a talent or a gift in the future life. When it is not complete, there will be tools inserted in the following plan to help us out.
From one life to the next, the individual has to do all the work toward mastery but lots of assistance comes with it. The natal chart allows us to see what the tools are, what the plan is, what the resistance (karma) is, and what the best way to set oneself free from the plan is. Indeed we are never requested to follow the plan since it is given to us to support the awakening that the physical reality is an illusion. The plan is always limiting. We will follow the path of limitation and destiny until we realize that we are a cosmic being with the power to manifest, not a mortal human being stuck in the limits of time and space.
If one surrenders totally to the spirit within, the liberation from the plan and the wheel of reincarnation is at hand. The surrendering of the mortal self to the immortal spirit within brings a new set of natural laws into action. One begins to be in the world but not of it. One becomes a master of the physical reality instead of being limited by it.

