Abraham and Isaac

God tells Abraham that he needs to go up on a mountain and sacrifice his son, Isaac, as a burnt offering. Abraham is sad that he has to kill his son but goes ahead for his faith in God. He takes Isaac up on the mountain under the impression that they will sacrifice a lamb. When they get there Abraham ties up his son and right before he kills him an angel appears and gives him a ram. The angel told him that God knew that he feared him because he was going to sacrifice his only son.  So, instead of sacrificing Isaac he sacrifices the ram. God tells him that he is blessed and that he will make his descendants plentiful because Abraham did not withhold his son.

True sacrifice is doing something that is not in your own benefit but is in the benefit of others. The people that come first to my mind that give true sacrifices are the armed forces. They fight for their country every day knowing that it could end badly for them.