Mutations act independently and we have not seen an example ever of a mutation depending on the existence of another mutation in order to happen. Natural selection is the idea that some animals die and some live because of environmental pressures. I don't think anyone disputes that this happens. But natural selection, far from being a process which develops forms of life, is actually a process which destroys them, leaving the survivors to do the best they can. When a species has lost the ability to vary enough to survive through changing times, we refer to that species as endangered or, if it is too late, extinct.
Natural selection is actually a process of killing off.
And it cannot 'select' from what is not already there. So natural selection is really of no help to evolution if a person looks at it straight on. So, actually, one does not need the Bible or Christianity at all to confront Darwinism. It fails on its own. I hope that helps.