Occasionally I run into someone, or hear of someone (usually someone else, as it happens) who claims that God 'could have used evolution', or 'could have used long periods of time to do his creating'. They usually advertise these claims with the smug triumphalism that such speculation proves some point. I don't know what that point could be, of course, because there is no point at all made by idle speculation.
One may as well claim that God could stand on his head!
Lita Costner in a recent article in Creation magazine starts with quoting this sort of vain claim; to rebut it, of course; but I think that her rebuttal could go further.
The theological point that she makes is appropriate, with the implications for the very goodness of the creation being imperiled by the contradictory (you could say incoherent) presence of the last enemy in its basic makeup, but there are other considerations that bear on the question, in my view.
God's revelation is not only a representation of what he has done, but, because God is a unified being (but not a unity, being in three persons), that is, there is no separation of who he is, what he wills or thinks and what he does, as there is with us, his revelation is also a representation of him, when it addresses his acts or relationships.
So, to claim that God could act slowly through error-prone chance processes to produce something that is purpose rich on many levels seems absurd at best; but given that the revelation is all the other way: the creation occurred quickly in direct response to his will, and this as part of God's claim on our worship, representation of him who is love, it is more than absurd. One could say it refers to another god, if it makes any god-reference at all.
Could God have created over billions of years? Which 'god' in which 'world' would that be that you are referring to, now? Our God, who represents himself as his revelation sets out? I think not. He explains his relationship to his creation in completely different terms, predicated on fellowship, not distance.
The damage this does goes beyond events in the world, to the way the world is structured. There is an at least implicit ontology in the creation account; it tells us a lot about reality, how it is structured, and the concreteness with which it 'operates'. To set this aside evaporates the Bible's ontology that comes out of the structures in the creation account, and must invoke an alternative; but this time, not implicitly. The alternative has to be developed explicitly as it denies there is one from the will of God, as it denies that the creation account has concrete content that makes sense in the categories of this world: the world it relates to by referring to its categories, and therefore has no ontological content. Yet any alternative ends up conjuring up a different god and falls into idolatry by proposing a different kind of reality, from an ontology that is structured on other than the God who is, and who speaks.