Here are some ways to understand the meaning:
* Acceptance: The speaker has come to terms with the fact that something is happening or has happened, and they are choosing to accept it as reality.
* Resignation: The speaker may feel powerless to change the situation, and so they are choosing to let it be.
* Submission: The speaker may be submitting to a higher authority or to fate.
* Passive acceptance: The speaker is not actively engaging with the situation, but simply allowing it to happen.
The phrase can be used in a variety of contexts, both personal and formal. Here are some examples:
* Personal: "I tried my best, but it wasn't enough. Let it be so."
* Formal: "The decision has been made, and we must respect it. Let it be so."
In summary: "Let it be so" is a phrase that reflects a state of acceptance and resignation. It conveys the idea of accepting a situation, even if it is unpleasant, and allowing it to happen.