How could rejecting the doctrine of creation ex-nihilo suggest that God is not all powerful?!?!
The Bible both teaches that God is all powerful and also contains no hint of creation ex-nihilo.
Peter Hayman records:
“Nearly all recent studies on the origin of the doctrine of creation ex nihilo have come to the conclusion that this doctrine is not native to Judaism, is nowhere attested in the Hebrew Bible, and probably arose in Christianity in the second century C. E. in the course of its fierce battle with Gnosticism.” (Peter Hayman, “Monotheism – A misused word in Jewish Studies?”)
Stanley L. Jaki, a Catholic priest of the Benedictine Order, stated:
The caution which is in order about taking the [Hebrew] verb bara in the sense of creation out of nothing is no less needed in reference to the [English] word creation. Nothing is more natural, and unadvised, at the same time, than to use the word as if it has always denoted creation out of nothing. In its basic etymological origin the word creation meant the purely natural process of growing or of making something to grow. This should be obvious by a mere recall of the [Latin] verb crescere. The crescent moon [derived from crescere] is not creating but merely growing. The expression ex nihilo or de nihilo had to be fastened, from around 200 A.D. on, by Christian theologians on the verb creare to convey unmistakably a process, strict creation, which only God can perform. Only through the long-standing use of those very Latin expressions, creare ex nihilo and creatio ex nihilo, could the English words to create and creation take on the meaning which excludes pre-existing matter. Stanley L. Jaki, Genesis 1 Through the Ages (Royal Oak, Mich.: Real View Books, 1998), 5-6
In the Bible God does not start with nothing.