Our sun is just a tiny yellow star in a vast collection that could support life. You'll hear this more and more. Don't believe it. The minimum requirement of a life-supporting star is missing from all the other stars. Our God-given sun appears to be unique. Appearing bright from our perspective on earth, the sun obviously has a special status for us. But its brightness is impressive only because it lies so close compared to the stars. Given everything we now know about the brightness of other stars, it’s fashionable today to call the sun a star, even an average star. But is that really the case?
While the sun has many characteristics similar to stars, the Bible never refers to it as a star. This suggests that the sun may have some unique characteristics. Could that refer to its composition? The sun's composition is a bit unusual -- it has far less lithium than most stars do. Lithium isn't very common in stars anyway, but the sun is among the most lithium-poor stars. Though this statistic is interesting, it isn't clear whether it is significant.
The sun has another property that is very important and unusual -- its stability. Astronomers have spent some time looking for stars similar to the sun, because such stars might be conducive to sustaining life on any planets that orbit them. Astronomers have found a few solar twins that have the same temperature, size, mass, and brightness as the sun, but nearly all of them are variable. That is, they vary in brightness. With all the concern about global warming today, it ought to be obvious that a constant sun is essential for life.
The sun may vary slightly in brightness, but it is beyond our ability to measure. So we can be confident that any normal variation is so small as to have few adverse effects on life.