It means a complete conquest of life's perennial tendency to lag behind the best possible; willing acceptance of hardship and pain.

And if we ask how this can be, what it is that makes possible such enhancement of human will and of human courage, the only answer seems to be that of the Johannine Christ: that it does consist in a more abundant life.
In the second chapter of this book, we looked at the gradual unfolding of that life in its great historical representatives; and we found its general line of development to lead through disillusion with the merely physical to conversion to the spiritual, and thence by way of hard moral conflicts and their resolution to a unification of character, a full integration of the active and contemplative sides of life; resulting in fresh power, and a complete dedication, to work within the new order and for the new ideals.

There was something of the penitent, something of the contemplative, and something of the apostle in every man or woman who thus grew to their full stature and realized all their latent possibilities.

But above all there was a fortitude, an all-round power of tackling existence, which comes from complete indifference to personal suffering or personal success.

And further, psychology showed us, that those workings and readjustments which we saw preparing this life of the Spirit, were in line with those which prepare us for fullness of life on other levels: that is to say the harnessing of the impulsive nature to the purposes chosen by consciousness, the resolving of conflicts, the unification of the whole personality about one's dominant interest.