Lut did not recognize who they were.
You are people unknown to me
When the guests entered, Lut said you are people unknown to me. He knew how dangerous his town was for strangers. He did not yet know they were angels, or what they carried.
Something new walks into your life: a diagnosis, a move, a person. You feel uneasy because you cannot place it. Lut did not understand either, at first. The meaning came a moment later.
If I cannot make sense of this right now, something is wrong.
Even a prophet did not see the meaning at first; understanding can come a step later.
When something unclear happens today, say: O Allah, show me the good in this, and wait.