Student or Learner
1. One of the most difficult things to make up our minds about it in what freedom consists.
>> May I change in what into where?
I assume your it was intended to be is.
Your expression would then be acceptable but very formal. Less formal would be:
One of the most difficult things to make up our minds about is what freedom consists in.
Even that sounds a little formal to me; I would use of rather than in