You reap what you sow means that everything that happens is a result of things that you have done in the past, and you may suffer the negative consequences of your actions.

For example:

It seems to me that if we create areas of such bleakness and social deprivation, we should expect to reap what we sow.

Parents who neglect their children will reap what they sow. 

It seems to me that if we neglect these people in our society, 

we should expect to reap what we sow.

He may have suffered, but I believe he reaped what he sowed.

Some employers have not treated their workers well, and now they are reaping what they have sown.

Tradução: você colhe o que planta- quem semeia, colhe- receber o que se merece.