If or since, does it make a difference?
In these sentences below, does it makes a difference if I replace *if* with *since*? 1）*If you are unemployed, why did you leave your last job?* 2）*If you are innocent, why did you flee?* 3）*If you are a Christian, why do you believe in a personal God like this?* My questions: 1. Does *if* here suggest a hypothesis, which means anyone who speaks these words is not sure or does not admit the fact? 2. Does replacing *if* with *since* make the clause a fact rather than a hypothesis? 3. If replacing *if* with *since* does make a difference, can *if* still be used if the context can imply that the clause is indeed a fact? Thank you in advance!