Calling divine power effective power affirms its perfection and genuine relation to possible outcomes. But effectiveness does not mean that every possible object must already exist eternally. The power is eternal; a possible thing is created in its appointed state and time.
Objection: if power has always existed, why has its object not always existed?
Reply: the attribute of power and the occurrence of a particular effect are different considerations. The possibility of an act is not denied because it becomes actual only at a specified time. Thus power is not reduced to an ineffective potential, nor does its eternity make every creature eternal.