We reincarnate time and time again to experience life and grow in consciousness and understanding. Karma gives us experiences in Life through which our souls can learn and develop.
There are some spiritual laws that show up in karma that people have in a particular lifetime. The spiritual aim of the game of life is to get through the allotted karma for that life. One law is the Law of Saturation. This means that a person gets saturated with one type of situation or experience in their life repeatedly until the soul is saturated with it. Or they may have as many lives as is required of a certain type of experience. For instance, a person can have quite a few lives (say, thirty or more) where they get to look after one particular person and develop their love and their heart centre. Once the person/soul has had enough then they move onto different karma with different situations happening.
Another law that applies a lot to karma is the Law of Opposites. This law often occurs in reincarnation. As an example, in one lifetime a soul can be in a female body, in the next lifetime the soul will be in a male body.
Another example, in one lifetime the soul can be in a personality that is very wealthy. In the next lifetime the soul can be in an existence where it experiences poverty. (The karma is different if a person has used their wealth for the benefit of others rather than being selfish). The Law of Opposites balances things out nicely, and to the soul it is all experience to learn from. That doesn’t mean to say that the personality enjoys the experience, as their attitudes and opinion of what they are going through depends on what the personality mind is like. If they have a “glass half-full” kind of mind, they will enjoy it.
Yet another example, a person/soul can be an aggressor one lifetime and a victim in a future lifetime, quite likely with the same soul. Souls have tended to come into creation in soul families so a soul is likely to have come across the same souls repeatedly, but in different circumstances (friend, enemy, brother, sister, parent, child and so on). On the inner planes, a higher aspect of ourselves will arranging who comes down to do what and with whom. What goes on down here in creation is our karma being worked out with our fellow souls being involved in the goings-on as well.
The Law of Opposites can show up in other ways in the kind of lifetimes we have. Souls have lifetimes where they are linked to the dark lodge, where they learn about and experience lives getting up to no good. On the opposite, souls have lifetimes being linked to the white lodge, and doing good. The karma gets balanced out – usually.
Souls have lives where they are brilliantly clever, and lives where they are slow thinking. They have lives where the soul experiences what it is like to be physically beautiful and lives where they are not physically beautiful.
Where a soul has hurt or killed others in one or more previous lives, in other lives they do the opposite, in a healing capacity or saving lives, perhaps sacrificing their own lives to do so. In these ways, karmic debts are paid.
Souls will have lives where they are not interested in spirituality, and lives where they are (like this one if you are reading this).
There are many other examples of the rich variety of experiences and lives that the Law of opposites generates. What has been mentioned above is only a small part of what is possible, and doesn’t even include examples of lives a soul will experience in the mineral, plant or animal kingdoms.