Unless you can name them, there are no defenses at all, let alone scientific. There is, however, a large body of apologetics, being explanatory of the material within the realm of Christian thought. Science and belief occupy different domains of inquiry, although religious institutions will deploy science in select cases, such as authentication of no known natural causes of miraculous events.
Mainline Christianity denies Creationism, and thus Christianity at large should not be characterized as supporting the idea. "Mainline" refers primarily to Christian sects who trace their origins directly to the first church in Rome and therefore encompasses the vast majority of Christians (Catholics, the Anglican Communion, Lutherans, Orthodox Churches). All these churches accept evolution as the reasonable explanation of the origin and development of life.
Here and there, you will find dissenters who claim otherwise, and they are, typically, members of fundamentalist sects. They neither speak for nor represent the opinions of most constituents of the Christian faith.
Otherwise, more sweeping considerations such as the very existence of God, and of his nature, fall within a scope of understanding which is outside the realm of scientific inquiry, owing to the fact that science, by definition, deals only in subject matter which can be scientifically evaluated.
I trust this answers your question.