Welcome to the forum loveneverfails.
the annihilation of souls concept, something we've come to call the 3 doors theory, was one of the most reviling, eyeopening, and relieving things I found in Yada Yahweh. And it makes logical sense as well.
The way I have come to explaining it to people, is by first teaching the difference between a soul and a spirit. most basic point on this is that they are different words and where chosen to convey different concepts. A spirit is eternal, and cannot be destroyed, even by Yahweh apparently, as Yahweh we are told will lock Halal Ben Shakar in the abyss for eternity rather than destroying him. A soul on the other hand is mortal. Proof that the soul is mortal is found through a careful study of Genesis, namely that the word in Hebrew for soul, nephesh, is also the Hebrew word for creature, and in Genesis, it is translated both ways in the span of only a few lines. It is translated living creatures in one verse, when talking about animals, and soul a few verses latter when talking about man. The Hebrew for both is Chay Nephesh. So unless one believes that animals have an immortal soul, the idea of a soul being immortal makes no sense. As well the Hebrew word nephesh also means Mortality. So by definition the soul is mortal.
The distinction between man and animals is not a soul, but a neshama. The neshama is for lack of a better word your conscience, it is the ability to decerne right from wrong and make a choice. The neshama is what gives us the ability, and yearning to know God. It is also what gives us the ability, through knowing Yahweh to become immortal with him. And so by leaguing ourselves with the source of life, and accepting His gift of salvation, we are born anew from above, a spiritual birth where by our soul is made immortal because it has been born of spirit. There is however a catch to the neshama, we can choose wrong as well as right, and we can choose to league our mortal soul with a spirit other than Yahweh, namely Halal Ben Shakar. By doing this, our soul becomes immortal as well, and as an immortal being one can not be destroyed, and therefor when Yahweh locks Halal in the abyss for all eternity, those who have been born of a spirit from below, those who have been born of Halal's spirit, are imprisoned with him. But inherent in the ability to choose right from wrong is the ability to choose neither. Those who choose neither receive no spirit and are not born of spirit at all, and as such are not immortal, and cannot exist in a spiritual realm. Therefore upon the death of their body, their soul will simply cease to be, following it's natural course. The vast majority of people in the world are in this third category. The only souls that will be in the abyss for eternity, are those who have intentionally leagued themselves with Halal, either for political, material, monetary or other such gains. People like Muhammad and Constantine are in this group.
Another point I like to make on this, is the difference between choice and free will. To start with, we must accept that "Angels", more accurately Spiritual Messengers, have the ability to choose. This is proven by virtue of the fact that Halal Ben Shakar choose to rebel against Yahweh, and a score of other Angels choose to follow him. But Angels do not have Free Will. And since Yahweh did not give them Free Will, they are punished for their choice. Free Will is the ability to choose with out fear of punishment, and this is what makes mankind different. If as men we choose to rebel against Yahweh, as long as we don't drag others down with us, Yahweh says fine have fun, and lets us go down that path, to it's natural conclusion, if that is bad for us, i.e. the annihilation of our souls, it is because we choose to go down that path despite his warning. The only "rule" that Yahweh has that he "punishes" for is he doesn't want us interfering with others free will. And even with this the punishment is not so much punishment as it is letting the natural consequences fall. By leading others astray, you have leagued yourself with a spirit, Halal's, and you can not be destroyed, but in the "next world", since you didn't accept Yahweh, you cannot be with him, you choose to be apart from him, and so you will be apart from, for all eternity, and you will be conscious of it because you are immortal, by choice. Yada uses the analogy of the Military for how Angels function, and I think it is a good one. A soldier, can choose to disobey and order from a superior officer, but by doing so he is kicked out of the military, and usually court marshaled and thrown in the jail. Mean while if I choose to disobey a request or order from a five star General, nothing is going to happen to me, unless he is telling me to get out of the way of a moving vehicle, in which case I will suffer the consequences of my choice. And if I'm throwing someone else in front of the vehicle with me, I will be throw in jail. Not a perfect analogy, but you get the idea.
That is my take on it at least.