Origin
Origin of this proverb is found in the religious book-Bible, Galations VI (King Jamesw Version); whatsover a man soweth, that shall he also reap.
Explanation
‘As you sow, so shall you reap’ is a proverb which means that actions or deeds of a person repay him/her in kind. If you did bad things in the past, you will get bad results in the future, if you did good things in the past, you will get good results in the future. Our life is nothing else but it is just like an agriculture soil; if we want good crop from this soil then we must sow the good seeds in it; because quality and quantity of the crop completely depends upon the quality and quantity of seeds we have sown. If one sows the seeds of grasses, one shall harvest the crop of grass and not a cereal crop like wheat or rice. He has to sow the seeds of wheat or rice to harvest the grain or cereal crop. We are only persons in this world, responsible for the effects of our actions.
Examples
That man was a criminal a few years ago, and now he’s in jail. As you sow, so you shall reap.
Mary was always kind to everyone. She volunteered, gave money to charity, and helped the homeless. As you sow, so you shall reap. She just won the lottery!