You seem to be including a whole bunch of things under the generic umbrella of "Evolution", geology, fossils, abiognesis, the Big Bang among others.
The reason to study those things is that the Biblical Creationist models did not explain what was seen in the record. The reason to accept the findings of those studies is that they better explain the evidence seen than any model yet presented by the Biblical Creationists.
Aslan is not a Tame Lion