The Thessalonians verse is somewhat of a restatement of the verse in Gen 3:19: By the sweat of your brow you will eat your food until you return to the ground, since from it you were taken; for dust you are and to dust you will return." The Work of man and his Sustenance are connected with the Curse. Until the curse is removed, man earns his bread by sweat. In the Kingdom, possibly it is a gift of God (like manna), for we are told to pray: "Give us this day our daily bread," and in any case, the source of our sustenance is as it says in Deutonomy 8:3: Man shall not live by bread alone, but by every word that comes from the mouth of God.
Agree with the above. Note that the verse says if a man "will not" work. It is a deliberate choice to be lazy. It does not say "can not" work, such as a disabled person or someone otherwise incapable of working. The Pilgrims discovered this principle when they tried a form of communal (communistic) government and men would not work, since everyone got the same anyway. They switched to personal responsibility and immediately began to grow and prosper (roots of capitalism); and the rest is history.