The following section is taken from The Teaching Of Buddha courtesy of the Bukkyo Dendo Kyokai (Society for the Promotion of Buddhism). It shows us how Buddha neither appears or disappears; rather, Buddha always is.

When the moon sets, people say that the moon has disappeared; and when the moon rises, they say that the moon has appeared. In fact, the moon neither goes nor comes, but shines continually in the sky. Buddha is exactly like the moon: He neither appears nor disappears; He only seems to do so out of love for the people that He may teach them.

People call one phase of the moon a full moon, they call another phase a crescent moon; in reality, the moon is always perfectly round, neither waxing nor waning. Buddha is precisely like the moon. In the eyes of men, Buddha may seem to change in appearance, but, in truth, Buddha does not change.

The moon appears everywhere, over a crowded city, a sleepy village, a mountain, a river. It is seen in the depths of a pond, in a jug of water, in a drop of dew hanging on a leaf. If a man walks hundreds of miles the moon goes with him. To men the moon seems to change, but the moon does not change. Buddha is like the moon in following the people of this world in all their changing circumstances, manifesting various appearances; but in His Essence He does not change.