A statement in writing must be made, signed by the defendant, and verified by affidavit, to the following effect:
(1) It must state the amount for which the judgment may be rendered, and authorize the entry of judgment thereon;
(2) If it be for money due, or to become due, it must state concisely the facts out of which it arose, and must show that the sum confessed therefor is justly due, or to become due;
(3) If it be for the purpose of securing the plaintiff against a contingent liability, it must state concisely the facts constituting the liability, and must show that the sum confessed therefor does not exceed the same.