It becomes in that case a responsibility, which requires for its fulfillment a certain kind of behavior on the part of himself and his fellow-Americans.

And when we attempt to define the Promise of American life, we are obliged, also, to describe the kind of behavior which the fulfillment of the Promise demands.
The distinction between the two aspects of America as a Land of Promise made in the preceding paragraph is sufficiently obvious, but it is usually slurred by the average good American patriot.

The better future, which is promised for himself, his children, and for other Americans, is chiefly a matter of confident anticipation.

He looks upon it very much as a friendly outsider might look on some promising individual career.
The better future is understood by him as something which fulfills itself.

He calls his country, not only the Land of Promise, but the Land of Destiny.