Moses is told “This renewal (of the moon) is the first of renewals (of the moons)”. With these words the Jewish people were given their calendar, one using lunar months but faithful to the seasonal cycle of the solar year.
Unlike the solar year, where nature undergoes fundamental changes throughout the cycle, the lunar cycle engenders no changes to the moon or indeed, the earth. The only substantial change is our perception of the moon –how much of it we, on Earth, can see.
This tells us something powerful: Count, live, according to the Moon, to your perception as articulated in the Torah. What is ultimately important is not raw existence- but how we perceive it, how we use it, how we elevate it.
We perceive the Brightness of the Moon -e.g. the G-dly presence and potential in using the world for the positive things we are asked to do. We perceive the Darkness- the negativity of relating to the world in way we are asked not to it. It is this perception that we choose; this perception is the true purpose and reality of the Cosmos, far more real that anything that we might at first glance consider concrete and immutable.