The most similar is the opposite
the closest concept of the thing or some idea is the opposite
The fact that if u believe on something indirectly u believe on its opposite, u can know the thing from its opposite and in a philosophical path if the opposite doesn't exist the thing itself can't exist, they are related to each other.
This rule Applied on everything (Life, death)(Yin, yang)(Matter,antimatter)
What makes that more strange the two entities or the opposites come from the same root as an example Life, death they're opposite but they come from the Same root God , God is the one who gives Life and death, the god is the only one without any opposite, u may say satan but does Satan represent all the features and characteristics of god in one entity, the answer is no
112:1:Say, “He is Allah—One ˹and Indivisible˺
