Greater love hath no man than this, that a man lay down his life for his friends. (John 15:13)
I believe learning to love people enough that you would be willing to give up heaven so they could reach it is the heart of the concept articulated in this verse - and the best way to determine if you have reached that type of love is if you are giving up your picture of the ideal life HERE on earth in order to make others’ lives more ideal HERE on earth.
I believe in the idea of creating Heaven on earth - and that those who "really get it" are far more focused on helping those around them in the here and now than on securing a reward in the hereafter, specifically because they know their Father and love Him enough to sacrifice their all, if necessary, to do what His Son did when He was here. He spent His life ministering to the poor and despised and rejected - giving up the comforts He could have enjoyed in order to mourn with those who mourned and comfort those who stood in need of comfort.
One simple, minimal example: I believe that someone who can afford to pay a generous fast offering and does not do so does not understand the Gospel very well. That person, in my opinion, has put his own luxuries ahead of others' needs and is not living the foundational heart of the Gospel.