I have learned that the people of the Ancient Middle East believed there were several ways the gods proved they were gods. While they have no direct bearing on how one obtains salvation, knowing what these methods of declaring deity were can help us to better understand some of the more puzzling passages in our Scriptures. For example:
The power to speak something into or out of existence:
This is evidenced in Genesis 1:1, when Yahweh speaks the universe into existence. It is evidenced throughout Scripture, when the Lord is said to be able to either bring something into existence, or to kill or remove it the same way. The power to do by the spoken word alone was considered a sign of deity in the Ancient Middle East. Therefore, when Yahweh creates or destroys by the spoken word alone, He is demonstrating that He is God.
The power to impose order on or bring order out of chaos:
This is also evidenced in Genesis. In Genesis 1:2, The Lord is hovering over the void, and darkness was over the deep. This is the image of a boundless sea, which — to those in the Ancient Middle East — represented chaos, as did the sea monster. Therefore, when Yahweh creates order out of this vast void of chaotic sea, He is demonstrating that He is God. A subset of this principle is found in:
The power to slay the sea monster:
This is one of the signs of deity that we modern Westerners often miss — mostly because we have lost touch with the culture from which the Scriptures came. In the Ancient Middle East, the figure of the sea monster represented the forces of chaos. Therefore, whoever could kill the sea monster was demonstrating that they are a god. Therefore, when the Scriptures tell us that Yahweh crushes the head of the sea monster (Psalm 74:13), the Scriptures are telling us that Yahweh is God.
The ability to slay or defeat another god:
Here again, modern Westerners will usually miss the background behind passages that mention Yahweh defeating foreign gods. But, to the Ancient Middle East, the ability to defeat or kill another god not only meant that you were a god, as well, but that you were a more powerful god. Therefore, when the Scriptures tell us that Yahweh has put Bel to shame and shattered Marduk (two gods of Babylon), it is proclaiming Yahweh to be the most powerful of all Gods (Jer 50:20).
Note: Scripture mentions many other gods which Yahweh defeats or humbles.