Deadlock not possible?
Lets say for the sake of argument we have 6 units of memory available and three processes in a current state where each holds 2 resources. Each process needs 3 resources to finish and release its memory units to use by the others. This state is not safe, in fact this state is deadlock. Each needs one extra memory unit to finish, but this would require another process to release its units. No ordering of these 3 processes will be safe. 

You are not looking at the state of the program, but the entirety of the program, in which case, with no new resource creation and single threading, every state is safe.

Edit for clarity: From the definition of a state: "In computer science and automata theory, the state of a digital logic circuit or computer program is a technical term for all the stored information, at a given instant in time, to which the circuit or program has access". 

The import point is "given instant". The state could be at the initial state as your argument would require, or it is at some arbitrary point in execution