As a Christian I am always wary of two things when it comes to scientific advancement (especially of this type). First, that Christians will demonize something that can be life changing, and second, that the advancements will be used in ways that are ultimately detrimental to humanity by those with low moral standards.

In the former case, I can see my fellow Christians being duped by illogical arguments about "playing God" when they do not apply. In the latter, I can see individuals in power (Christian and otherwise) using gene therapy to devalue human life in certain areas of application i.e. warfare, abortion, etc.

Still, this is the story of medical advancements for centuries (if not longer). I hope the net gain is good. I would love it if my grandchildren could forgo illness and disease they would otherwise have had to live with.

In general, my message to Christians would be that this has all sorts of positive outcomes from the perspective of someone with a Christian worldview. Imagine if you could remove the argument in favor of abortion based on genetic disease. Imagine if you could live longer and healthier in order to accomplish more towards your ultimate purpose of glorifying God. These are just a couple of ideas off the top of my head, but the overall idea is that it does not have to be dismissed as black magic simply because you hold a Christian worldview.

To everyone with the ability to wield this power I would say, hold the sanctity of human life in high regard or you are undermining the entire purpose of advancements such as these. You need not have a Christian worldview to see that a low view of human life is detrimental to humanity even from a purely biological perspective.