If our lives and our awareness of our existence is all we have, then the value of life is magnified by its scarcity. Things that are limited in quantity are also the ones that become invaluable. So, if life is all you have, and death is certain, won’t you work your best to beautify it, to have others help you beautify it, and promote reciprocity? Evolutionarily and logically, promoting this benefits you.
A god that creates a child to be born dead where its death goes unnoticed, is a failed god for indulging in a purposeless creation. You haven’t really explained this problem that your belief has to square with.
I think I have adequately explained that you have no way of knowing what purpose such an entity would have in anything it did, because you are not such an entity. It is like an insect watching through a window as a mathematician does calculus.
Your argument might work for preserving YOUR life, but children are born every day, all over the world. We have no reason to care about a child who dies or a man who commits suicide. And why would you promote reciprocity, especially if reciprocity is inconvenient for some individuals (e.g women who abort for financial reasons), and might deny them opportunities in life? If we die, and that is all, there is no logical purpose for our existence other than to indulge ourselves in as much pleasure as possible. We are simply a happy coincidence of evolution. We have no reason to concern ourselves with the continuance of the species. Why? What possible benefit could come to you by promoting reciprocity in others? A warm feeling inside that you helped the species? This is illusory.
When you place value on something, this is subjective to a large extent. One man’s trash is another man’s treasure. If Ted Bundy said that the lives of his victims had zero value, but you said that they had high value, who is right? He perceives the life as trash, you perceive it as treasure.
Now, in a world with God, Ted Bundy is wrong. Human life has objective moral value placed upon it by its creator, whose value is indisputable. Bundy has violated a commandment given from creator to creation.
In a world without God, neither you nor Bundy are right or wrong. You simply have a different assessment of the value of human life. Bundy is doing nothing more wrong than behaving unfashionably, or straying from the herd in his beliefs.
Reciprocity is simply a mechanical function of our nature, the same for all other animals. We are compelled to reproduce by biology. Our reproduction serves no greater purpose than a ferret’s reproduction. Any greater value of our continuance that humans place, is illusory. At least, in a world without God.
And as a side note, reciprocity does help with our continuance as a species, BUT it is not necessary.