Rudolf Steiner has some deeply suggestive things to say about this matter; in which he subtly asserts that the spiritual in life is to be found in exactly those aspects that are taken for granted - the backdrop of 'normal', everyday assumptions and experiences of things going well, not collapsing or exploding.
In a different way, he is making the same recognition that I came to in respect to the science of biology; when I realised that there 'must be' a vast positive, creative, purposive background in order that biology be possible.
This seems extremely difficult to describe with any precision; perhaps because it is the ocean in which we dwell; but it goes far beyond any specific instances (such as synchronicity) to notice that there are innumerable things that must 'go right' at every moment of every day; if The Whole Thing is not simply to collapse into chaos.
We should not really take for granted all the ways in which we don't die, and continue to perform innumerable functions and fulfil innumerable tasks (like walking down the street from one end to the other!).
As I say, it is to big and all encompassing really to 'explain' in the same way that we can explain smaller and more specific instances. But here are some excerpts from a lecture by Steiner (GA 181 - Berlin,5th March, 1918 - excerpted as Lecture 9 here) which may be helpful.
...A man was accustomed to take a certain walk daily. One day, when he reached a certain spot, he had a feeling to go to the side and stand still, and the thought came to him whether it was right to waste time over this walk. At that moment a boulder which had split from the rock fell on the road and would certainly have struck him if he had not turned aside from the road on account of his thought.
This is one of the crude experiences we may encounter in life, but those of a more subtle kind daily press into our ordinary life, though as a rule we do not observe them; we only reckon with what actually does happen, not with what might have happened had it not been averted. We reckon with what happens when we are kept at home a quarter of an hour longer than we intended. Often and often, if we did but reflect, we should find that something worthy of remark happened, which would have been quite different if we had not been detained.
Try to observe systematically in your own life what might have happened had you not been delayed a few minutes by somebody coming in, though, perhaps, at the time, you were very angry at being detained. Things are constantly pressed into one's life which might have been very different according to their original intention. We seek a ‘causal connection,’ between events in life. We do not reflect upon life with that subtle refinement which would he in the consideration of the breaking of a probable chain of events, so that, I might say, an atmosphere of possibilities continually surrounds us.
If we give our attention to this, and have been delayed in doing something which we have been accustomed to do at mid-day, we shall have a feeling that what we do at that time is often — it may not always be so — not under the influence of foregoing occurrences only, but also under the influence of the countless things which have not happened, from which we have been held back. By thinking of what is possible in life — not only in the outer reality of sense — we are driven to the surmise that we are so placed in life that to look for the connection of what follows with what has gone before is a very one-sided way of looking at life.
If we truly ask ourselves such questions, we rouse something which in our mind would otherwise lie dormant. We come, as it were, to ‘read between the lines’ of life; we come to know it in its many-sidedness. We come to see ourselves, so to speak, in our environment, and we see how it forms us and brings us forward little by little. This we usually observe far too little. At most, we only consider the inner driving forces that lead us from stage to stage. Let us take some simple ordinary instance from which we may gather how we only bring the outer into connection with our inner being, in a very fragmentary way.
Let us turn our attention to the way we usually realise our waking in the morning. At most, we acquire a very meagre idea of how we make ourselves get up; perhaps, even the concept of this is very nebulous. Let us, however, reflect for a while upon the thought which at times drives us out of bed; let us try to make this individual, quite clear and concrete. Thus: yesterday I got up because I heard the coffee being made ready in the next room; this aroused an impulse to get up; to-day something else occurred. That is, let us be quite clear, what was the outer impelling force. Man usually forgets to seek himself in the outer world, hence he finds himself so little there. Anyone who gives even a little attention to such a thought as this will easily develop that mood of which man has a holy — nay, an unholy — terror, — the realisation that there is an undercurrent of thought which does not enter the ordinary life.
A man enters a room, for instance or goes to some place, but he seldom asks himself how the place changes when he enters it. Other people have an idea of this at times, but even this notion of it from outside is not very widespread to-day. I do not know how many people have any perception of the fact that when a company is in a room, often one man is twice as strongly there as another; the one is strongly present, the other is weak. That depends on the imponderabilities.
We may easily have the following experience: A man is at a meeting, he comes softly in, and glides out again; and one has the feeling that an angel has flitted in and out. Another's presence is so powerful that he is not only present with his two physical feet but, as it were, with all sorts of invisible feet. Others do not, as a rule, notice it, although it is quite perceptible; and the man himself does not notice it at all.
A man does not, as a rule, hear that ‘undertone’ which arises from the change called forth by his presence; he keeps to himself, he does not enquire of his surroundings what change his presence produces. He can, however, acquire an inkling, a perception of the echo of his presence in his surroundings. Just think how our outer lives would gain in intimacy if a man not only peopled the place with his presence but had the feeling of what was brought about by his being there, making his influence felt by the change he brings...