It is because of this common Bible metaphor that "father" was considered as synonymous (whether as "creator" or "procreator") with "source"! - See p. 190, Thayer's Greek-English Lexicon of the New Testament, Baker Book House, 1984.
"Of the author, or maker, of anything, specially of the creator.... And in this sense God is said to be `the father of men,' Is. 63:16; 64:8; [etc.]. All these ... come from the notion of origin." - p. 2, Gesenius' Lexicon.
Notice how the strongly trinitarian NT Greek experts, Dana and Mantey, explain this scripture:
"in 1 Cor. 8:6 the function of God the Father as the SOURCE of creation is distinguished from Christ's role as mediator of creation." - p. 1182, Vol. 3.
Also see The NIV Study Bible footnote for 1 Cor. 8:6: