You will not reap what you sow, this is just superstition. Many enormously selfish and greedy people live wonderful lives in mansions or penthouses and many good and honest people experience terrible misfortunes.
The idea that you will carry your good or bad deeds with you to the next life is of course also superstition, a belief which is not based on evidence or personal experience. To believe in the Karma theory is like believing that the earth is flat. It is the Hindu version of “You’ll get pie in the sky when you die.” or you’ll end up in hell.
Most spiritual seekers of today are still stuck in belief systems that are thousands of years old. Many people still believe in astrology and fairy tales about gods and angels. Many people are still prisoners in ancient delusions.
The age of enlightenment did not begin in the eighteenth century. The age of enlightenment begins now, in the twenty first century.