And as a side note, reciprocity does help with our continuance as a species, BUT it is not necessary.
So you're wrong, it is absolutely necessary for reciprocity to exist, for you to be part of what you call civilisation.
Any behaviour that threatens the human social fabric in turn threatens its constituent individuals. This is why disparate cultures evolved laws against murder and theft, against premarital sex and fatherless child-rearing, if not without your god, then with other gods. So again, without invoking your specific god, Ted Bundy's acts would be seen as immoral simply because they threaten the social fabric, and damage trust and collaboration were the society to condone such behaviour.
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.
Wrong. Caring for another's life fosters reciprocity. It builds trust and frees individuals from allocating all their resources against defense from one another, thus giving them a very tangible advantage in living and reproducing, totally in line with Darwinian evolution. Take a look at the nomad tribes in the world today. Without settling, their numbers are limited and even here, without collaboration, individuals don't stand a chance. If they do want to settle, collaboration by way of reciprocity is of paramount importance.
You neglect the evolutionary pressures that dominate our thinking and outlook, the ones geared to goad us into reproducing and raising offspring. A Muslim is devoted to raising a family in spite of following a wrong god, because of this. The evolutionary forces making people desire such an outcome are more universal than your specific religion, thus underlining the inherent truth of the former. The best environment for one's offspring to succeed in, is one that fosters reciprocity. Because you cannot always be there to protect them. This trust is not a mere luxury but a prime necessity. You pooh-pooh it as a "warm, fuzzy feeling" out of your incapacity to recognise its importance in your life, because you don't want your dogma to collapse under the weight of truth.
Your god in the voice of a man was happy in commanding men to slaughter infants in 1 Samuel 15:3. If you can excuse this, how can you say Satan is bad? Where did that inherent value of human life disappear suddenly, from those infants who couldn't possibly have done anything yet to earn them this fate? And if they did earn it because their "evil" was foreseen by your god, then why did it conceive them, and cause them to be birthed in the first place? And if they can be forced to a trial before the act was committed, why are you allowed a pass? Your dogma has holes that cannot be patched by logic and reason, and can only be given a pass by highly subjective bias.