prayers

We normally say to each other that kindly pray for me and they said  in formal manner that why not but is it  that in this way prayers really work 

I think prayers are the one which we earn with our good deeds true prayer is the one when you do some good deed and in return, someone says good words for you.

Even in the family, there are some children whom parents love them more than others they pray for them more than others because they give them more than others 

Prayers work but only when someone does it with heart.

Earn prayers for you not beg it for you.

So tell me guys what do you think that which prayers are best which we earn with our good deeds or the one which we beg?