Observing the moon is about light play on the surface. Every observation is dependent on the sunlight’s angle. The boundary of lunar day and night is called the terminator. The observing principle is pretty simple: high ground gets exposed to light; low ground is in shadow. So when you look at the observation sheet below for a particular date and time, you can see the lighter areas as high ground and while the darker areas are still in shadow. It was about one lunar cycle ago, so in just a day or so a person can see the same craters on the lighter side of the terminator. These craters will, however, appear a little different since the light angle will probably be slightly different. The same basics, however, apply. High ground is bright because it is in the light.
The parable is also simple: the parts of a life that are in the light are bright and exposed. The parts that are hidden remain hard to see. When a person comes to the God of the Bible, life gets exposed to the light. Deeds and their motivations, then, are seen for what they are by God. A person who refuses to come to the Light remains in darkness for fear that his deeds and their motivations will be exposed. Does that sound a bit harsh? It’s not my judgement. Jesus Christ makes the statement during a conversation with Nicodemus (see John 3:19-21). The good news is that exposure to his light saves us. One can go further with the analogy: the more Light we get, the brighter we get. So it is. The walk of a believer is purified as exposure to the Light continues. Likewise, things kept hidden (they really are not hidden to God) stay unchanged. That can happen when we try to protect our sin, mistakes, and short comings. He would rather purify us and set us free. After all, the work of the Gospel involves changing us if we will stay engaged.
On a creation note, the moon is an extra-ordinary creation, noted by God in Genesis 1:16 and several other locations. It’s placement does wonderful things to earth’s oceans and provides a natural time piece. It also invites observation because it is sizable compared to earth and is only a quarter million miles away. It was created that way; it did not create itself or place itself. The Bible is silent regarding the source of the cratering. Most scientists and specialists that believer the Bible’s creation account think it occurred around the time of the Genesis Flood. Regardless, it’s unique characteristics are manifold and it is an easy object to observe. The moon is one of God’s marvelous deeds.
For more information on learning to observe the moon, you can download the course on Astronomical Observing from a Biblical View. For information on biblical creation, download the Creation Study. Both courses are free. Look under <courses> drop-down menu.