'El ser' is a Spanish word which has such a profound meaning, it should be the first lesson everybody should learn. There is no good translation into English for the thought that this word conveys.
If I literally translated 'el ser' into English, it would be 'the being.' Then you would be thinking of a monster movie, and that's the wrong thought completely.
If I try to tell you a more relatable translation, I might say 'your being.' This too is disingenuous because this talks about you and who you are and not something you possess. You cannot possess who you are any more than you can grab air with your bare hands. You are who you are.
No, it is 'the being as in you' or 'you are the being' or even better 'the being who is you.'
Some may say, "Oh, your soul." Others may say, "Oh, your spirit." No! You are not your soul or your spirit. You possess a soul. You possess a spirit. The being who is you cannot be possessed.
The being who is you is a free person. The being who is you thinks. The being who is you learns. The being who is you loves. The being who is you hopes. The being who is you dreams.
There is nothing else like the being who is you. You are unique and irreplaceable.