What are universities asking for when they demand a "financial resource statement"?
The purpose of the financial resource statement is to determine if/how much aid you will need to complete the program. Most of the time, the most important things will be:


Any grants/scholarships/fellowships you will use to pay for your education.
How much in student loans you will use, and if they have already been approved (not common, but may happen).
Personal resources—including family support—you will use to support yourself.


Usually, a list is all that is needed, to show that you realize the costs of attending the program, have accounted for them, or are requesting appropriate assistance from the school. You don't necessarily have to show that you have the entire cost covered, either, especially if you are requesting aid from the University, as long as you show that you know the correct amount you need. Whether it hurts you or not in the application depends very much on the policy of the school.

If a school requires something formal, they will usually have a form you have to fill out. I would not provide any banking data, unless absolutely required. You don't know who works in the administration office.