THE vastness of the Lord’s heaven follows from many of the things that have been presented above, especially from the fact that heaven is from the human race (see Sections 311–317), not only that portion of it born within the church but also the portion born outside it (Sections 318–328). This means that heaven includes everyone who has lived a good life since the very beginning of our planet.
Anyone familiar with the continents and regions and nations of this world may gather what a multitude of people there are on our whole globe. Anyone who goes into the mathematics of it will discover that thousands and thousands of people die on any given day, making hundreds of thousands or millions every year; and this has been going on since the earliest times, thousands of years ago. All of these people have arrived in the other world, called the spiritual world, after their decease, and they are still arriving.
I cannot say how many of these are or are becoming angels of heaven. I have been told that most of the earliest people became angels, because they thought more deeply and spiritually and were therefore enveloped in heavenly affection; while for later ages it was not so many because as time passed we became more externally minded and began to think more on the natural level, which meant that we were enveloped in more earthly affection.
This enables us to gather at the outset that heaven is huge simply from the inhabitants of this planet.
The immensity of the Lord’s heaven may also be gathered simply from the fact that all children, whether born within or outside the church, are adopted by the Lord and become angels, and their number amounts to a quarter or a fifth of the whole human race. It may be seen above (Sections 329–345) that every child—wherever born, whether within the church or outside it, whether of devout or irreverent parents—is accepted by the Lord at death. Every child is raised in heaven, is taught and is permeated with affections for what is good according to the divine design and thereby with firsthand knowledge of things true, and is then perfected in intelligence and wisdom, so to speak, and admitted into heaven to become an angel. You can gather what a vast multitude of heaven’s angels has come from this source alone from the beginning of creation to the present day.
from Heaven and Hell, Sections 415, 416