D&C 56

We learn in modern revelation that -

"There is a law, irrevocably decreed in heaven before the foundations of this world, upon which all blessings are predicated—
21 And when we obtain any blessing from God, it is by obedience to that law upon which it is predicated."  (Doctrine and Covenants | Section 130:20 - 21)

That blessings are predicated upon obedience.  The Lord also taught -

"...that those of whom he shall receive may be rewarded again according to that which they do;
13 For according to that which they do they shall receive..."  (Doctrine and Covenants | Section 56:12 - 13)

But it is important to understand that it is what we do with that which we have been given for the Lord continues to teach -

"Wo unto you rich men, that will not give your substance to the poor, for your riches will canker your souls; and this shall be your lamentation in the day of visitation, and of judgment, and of indignation: The harvest is past, the summer is ended, and my soul is not saved!"  (Doctrine and Covenants | Section 56:16)

But this is not limited to the rich for -

"Wo unto you poor men, whose hearts are not broken, whose spirits are not contrite, and whose bellies are not satisfied, and whose hands are not stayed from laying hold upon other men's goods, whose eyes are full of greediness, and who will not labor with your own hands!"  (Doctrine and Covenants | Section 56:17)

The poor have an obligation to do for -

"...blessed are the poor who are pure in heart, whose hearts are broken, and whose spirits are contrite, for they shall see the kingdom of God coming in power and great glory unto their deliverance; for the fatness of the earth shall be theirs."  (Doctrine and Covenants | Section 56:18)

Obviously, there will always be rich and poor.  What it seems to come down to is when -

"...you seek to counsel in your own ways.
15 And your hearts are not satisfied. And ye obey not the truth, but have pleasure in unrighteousness."  (Doctrine and Covenants | Section 56:14 - 15)

This would be considered not doing therefore there is no reward.