"Here, if I am right, you're essentially saying you have chosen to follow "science" in a way because they have bettered society. I return to the morality argument and ask, why is bettering society and our life conditions a good thing?
You try to answer again that evolution naturally strives toward life. Why is this so?"
Bettering life conditions is better because as a biological organism I am subject to many natural wants such as hunger, fatigue, and thirst, as well as many less base wants. It's clear to me that it is pleasurable to have food, and not pleasurable to go hungry. It is in my interest to seek pleasure and avoid pain because I am more or less hardwired for this purpose, because for the most part pleasure coincides with what is good for me in terms of evolution, and pain coincides with what is bad for me. I don't mean to say that these things are good because they are evolutionarily good. I mean these things are good because they are pleasurable, and pleasure is more desirable than pain. I could not explain that to you more clearly and rely on your human empathy and common experience to agree, just as I could not explain to you the colour orange unless you had also seen it.
I admit that this argument is almost a tautology because bettering social conditions is almost synonymous with satisfying our wants. We'd like to solve world hunger, thirst, and cure disease. These wants exist whether you're atheist or theist, and I don't think God very explicitly tells you to eat because eating is a good thing, or cure disease because being sick is a bad thing but, and because, we all have a strong feeling that solving world hunger and curing the world's diseases are worthwhile endeavours. The Bible doesn't tell you why you need to satisfy so many wants simply to continue existing, I think we both take it as an accepted fact, and it's no surprise that the "betterment" of society is built up around this principle.
I thought I had already answered the question as to why evolution would instill in us a strong value of life and sense of preservation several times, but maybe I haven't been clear enough? Let's say we have two groups antelopes. One group has a strong self of preservation, the other one is ambivalent. They are in direct competition for resources that are scarce. There's only so much grass, and they must be wary of predators. The antelopes which value their life will eat the grass and run away from the predators because they know this is what they must do to continue living, which they value. The other antelopes have no compulsion to eat the grass or run from the predators because they're indifferent to whether they live or die. What happens? The ones with no value of life are dead. They've starved or have been eaten. The only antelopes left are the ones with a value of life. They reproduce as antelopes are liable to do (because they value reproduction, as can be shown to be advantageous by a similar example), and their offspring most likely inherent their value of life. It is no surprise then that almost every antelope has a strong value of life and will run for it's precious life when a cheetah comes up on the horizon. There might be a mutant every now and then that doesn't have this value, but it will quickly die, and will rarely be able to reproduce to pass on it's mutation. Does this make things clearer? A value on life is only one of the innumerable values that evolution has given us.