grammar - Why is it impossible to put a preposition in front of the relative 'that'?

There are two sentences like below,

1. I want to see the house in which you lived. (O)-correct


2. I want to see the house in that you lived. (X)-incorrect

We learned that we should not put a preposition in front of that (relative pronoun). But we don't know the reason why we should not put a preposition in front of that. I want to know the reason.