I recognize that your intentions are good. I also believe the discussion of the creation is not an essential in regard to Salvation.
Consider the possibility that in creating the universe God stretched the stars across the millions of light years instantaneously. The Bible describes it in that way. Light can be stretched like a scroll by God. The billions of years predicted by scientists is a materialistic view of a supernatural event. They have it wrong.
For the same reason the geology we examine is more consistent with a world wide flood than with any model science posits. As God created the matter that makes up our universe, who can say that in the process the atomic makeup was unbelievably accelerated. Scientists force themselves to disregard what we know to be valid data. Supernatural data.
Walking on water, raising the dead, transporting Phillip to the desert, appearing in a locked room, the virgin birth... All of these truths can play no part in science, because science must reject the unprovable. Science is good for some things, but inept at understanding our origins or our originator. We are forced to trust God's eyewitness description of what He did, and that He could accurately convey it to a human being for our admonition.
There is no reason to twist the revelation to line up with science. Science is limited in it's truth seeking apparatus.
I would suppose it's possible that God made a universe that *looked* billions of years old when it really is a young universe.
But a look at mitochondrial DNA poses a problem. You see, Darwin's evolution is just a theory in some ways, but GENETIC evolution is a proven law. We can actually measure how many generations human beings are removed from each other. With a big enough computer and a concerted effort, we could create a family tree of every single human being.
On one hand, the results are fairly amazing: We are actually all descended from a single mother, not all that long ago! This discovery is so shocking, the universal mother was actually dubbed "EVE" by scientists. On the other hand, whereas the bible records about 70 generations (plus 2000 years), the data shows about 1000 generations: tantalizing close, but significantly and inescapably distant from biblical projections.
I do agree with you that the discussion of creation is not essential in regards to Salvation. The problem is the widespread perception that science is antithetical to Christianity. Some of us must hold the door open for the salvation of scientists, and to allow Christians to study science.