The soul is not a "theological and abstract subject." The soul is the coolest, eeriest, most mysterious, evocative, crucial, sacred, eternal, life-directing, fragile, indestructible, controversial, expensive dimension of your existence. Jesus said it's worth more than the world.
So, shouldn't you get pretty clear on exactly what it is? Shouldn't you know what it runs on? Wouldn't it be worth knowing how to care for it? Two things are for sure. One is: you have a soul. The other is: if you don't look after this one you won't be issued a replacement.