James Allen's All These Things Added was first published in 1903 and contains both "Entering the Kingdom" and "The Heavenly Life", which were both later published as separate books. Allen writes:

EVERY HUMAN SOUL IS IN NEED. The expression of that need varies with individuals, but there is not one soul that does not feel it in some degree. It is a spiritual and casual need which takes the form, in souls of a particular development, of a deep and inexpressible hunger which the outward things of life, however abundantly they may be possessed, can never satisfy. Yet the majority, imperfect in knowledge and misled by appearances, seek to satisfy this hunger by striving for material possessions, believing that these will satisfy their need, and bring them peace.

Every soul, consciously or unconsciously, hungers for righteousness, and every soul seeks to gratify that hunger in its own particular way, and in accordance with its own particular state of knowledge. The hunger is one, and the righteousness is one, but the pathways by which righteousness is sought are many.

They who seek consciously are blessed, and shall shortly find that final and permanent satisfaction of soul which righteousness alone can give, for they have come into a knowledge of the true path.

It is the realization of this principle where the Kingdom of Heaven, the abiding home of the soul, resides, and which is the source and storehouse of every permanent blessing. Finding it, all is found; not finding it, all is lost. It is an attitude of mind, a state of consciousness, an ineffable knowledge, in which the struggle for existence ceases, and the soul finds itself at rest in the midst of plenty, where its great need, yea, its every need, is satisfied, without strife and without fear. Blessed are they who earnestly and intelligently seek, for it is impossible that such should seek in vain.