All living beings are alike,insofar as they are subject to the afflictions,yet there are many differences among living beings with which we all are familiar.For eg.Some of us are born in wealthy family while others are born in extremely poor conditions.Some are strong while others are diseased & so forth.There are many differences among human beings & there are even greater differences between humans & animals.Science does not have an answer for these differences (other than mere chance).Karma accounts for these differences among living beings.
Let us shortly look at the concept of Rebirth.There are basically 6 realms or dimensions of existence in which the migration of Soul takes place.These are divided into 2 groups-one that is relatively fortunate while other that is relatively unfortunate.
The first group includes the realm of Gods,demi-gods & humans.Second group includes the realm of animals,hungry souls & realms of hell.Simply put,Wholesome Karma results in the birth in first group while Rebirth in second group is the result of Unwholesome Karma.
An individual soul is trapped in the continuous cycle of Birth & Death.Human realm is the most favored of the above six realms because as a human being,one has the motivation & opportunity to practice Dharma & achieve Enlightenment.
Also an important point is that the effects of Karma does not last forever.Once the effect of Karma is exhausted,the soul is reborn in the lower or higher realms.
Nothing happens by accident in this orderly perfect Universe.Just as the law of physics,nature decides the circumstances in which living being finds himself according to the Law of Karma.
It is said that when we die,our soul has to leave our properties,loved ones & the physical body but our Karma follows our soul like a shadow.One can never escape Karma,neither in heaven/hell nor on Earth.So,understanding this concept not only discourages us from performing Unwholesome actions but also motivates us to cultivate Wholesome actions.
“As you Sow,so shall you Reap”