Well, if you don't revise, you walk into that exam with no knowledge.
This means you won't be able to answer the questions, which leaves you with coming out with very bad grades at the end of it.
There's no resits this year which means you have no second chances and if you do have a chance, you're most likely going to have to resit the WHOLE 2 years again, because of the 2016 A-Level changes. Now who wants to stay in college for that long?
Just knuckle down and make it to University and then rest. The motivation should be getting out of college and not failing your exams. You don't want to waste your years and most of all, you don't want to ruin your chances of getting that dream job of yours.