The Gospel is sent into the world to comfort the afflicted and to afflict the comfortable. Most believers have always been of lower classes. Rich in faith. By using poor, God cuts down human boasting. Inherit the kingdom - future millennium in view.
Snobbery is short-sighted.
The moral argument against favoritism. A. Love neighbor as self. Positive counterpart to above. It is summation of all other laws. We can only love people at eye level.