Consider that reality is, in the words of The HitchHikers’s Guide to the Galaxy, very, very big. Not just big in terms of space-time, but big in such terms that space-time itself is an expression of a strata of reality. Consider that, just as a three dimensional object will cast a two dimensional shadow, perhaps the only example of a two dimensional object that we humans can experience, then space-time is also a ‘shadow’ cast by a higher order of reality.
In this consideration, our soul is the higher order of reality to which we are its shadow. According to Baha’u’llah, our presence as a space time object has the particular significance of being able to know God and, in that, has the distinction of communicating with our soul and that communication is nurturing of the soul itself. The shadow communicates per force of its presence, by the shaping of the blotting out of light. The human being communicates with the soul through the recognition of its own ego and the effort to get that ego out of the way so that love, justice, forgiveness, magnanimity etc, can become the prime modus operands of the human being.
What, then, are the markers of spiritual development, of the nurturing of that soul. Surely such a higher order being cannot be evaluated on the basis of the space-time behaviour of the human being. Rather the nurturing is associated with effort rather than outcome. Otherwise, how could it be fair that a person who has had the benefits of wonderful parents, a fabulous education, and an abundance of material benefits, and who does great deeds in the world, be compared with a person born into poverty, an orphan, a slave and beggar. Even this beggar might apply great effort to know God, know himself, and develop compassions.
How then, does the experience of progress of civilization relate to the question of spiritual development? Does the development of a peaceful world mean that there is an equal development of spirituality? It might be best to see the relationship as a benchmark of the effort of the whole of humanity in spreading the ego, thinly.
There are two processes at play here. On the one hand, the effort by all human beings to become spiritually transformed, if successful, should lead to signs in the world such as peace, harmony and equity. On the other hand, as the contingent world provides the basis for the testing of the ego at each phase of human learning, it is necessary for each generation to have a modification to the test for it to be valid to the effort. In other words, if humanity could not progress civilisation then it cannot be said that human beings are applying effort. And, if civilization does not progress, creation itself is unable to apply an appropriate level of testing for human beings who are now quite habituated to the state of affairs. To wit, the test becomes too easy, and therefore not a test at all.
Thus, the progress of civilization is not only a sign of spiritual development, and maybe the best of all signs, it is also a sign that the spiritual test is also changed for a new generation of people with new powers. These powers also need to be tested for effort, not outcome, and thus the test must be commensurately different.