The main message of these 72 workers is the simple declaration "The kingdom of God is near." Dallas Willard once said that when he was a young boy, rural electrification was taking place throughout the United States. For the first time ever, tall poles popped up across the landscape of the countryside with huge electric wires strung from pole to pole to pole. But initially at least, not everyone trusted electricity and so not many rural families opted (for a time) to not hook up. They heard the messages of the electric company of how much easier life would be with electric washing machines replacing hand-cranked wringers and electric vacuum cleaners bringing to an end the old practice of hauling heavy carpets outside to have the dirt beaten out of them. They heard these promises but did not trust or believe them.
So in a sense, Willard wrote, you could have said to those folks, "My friends, electricity is at hand!" But if they opted to not tap into that power that was running right over their heads, then the nearness of the power would do them no good. Maybe the message of the kingdom's nearness was like that. With Jesus in the world, the kingdom of God was near, at hand. All the goodness and glory and power of that kingdom was right there, but if they kept it at arm's length, it would do them no good. Their lack of participation did not weaken the power of the kingdom. But it did land them in an unhappy (and unnecessary) spiritual situation of staying in the dark when the light of the world was right there.