Human value: intrinsic or instrumental?

So, I got into a discussion with a friend on Facebook (don't worry, he's one of those people who can actually talk on the internet without being a jerk) who posted an article about humans colonising Mars as a sort of race survival imperative.

My initial question to him was about why consciousness was worth saving, as well as why humans were worth saving if they were only going to blow themselves up anyway.

His argument to the second one was solid: so long as you do not view the value of perserving something as a dichotomy against its tendency to destroy itself, then self-destructive tendencies are simply a further argument for not putting all your eggs in one basket.

His position on the first, about the nature of the value of consciousness, was founded mostly, at his very gracious admission, on moral intuition. He then asked if there could be 'value' without 'evaluators'.

I stated my position to be that consciousness is not intrinsically valuable, but derives its value from existing within humanity, and that humanity derives its value from God. And to clear up a possible next step argument, asking about whether God is intrinsically valuable is a bit of a furphy, because when it comes to God, who is infinite, questions of things like value end up changing form to becoming definitional, because God isn't valuable, God is Value.

His excellent question in response to this was whether the Judeo-Christian idea of human value implies an intrinsic value in humanity, or rather simply posits an instrumental value on humanity insofar as they keep the faith or follow the law. He then posed a quandary, suggesting that this would be difficult to reconcile with God killing first born sons in Exodus 12, or making threats of terrible punishments on people who did not follow his law in Deuteronomy 28. He didn't like the idea that humanity was some sort of fungible worship device that could be supplanted by something else, so long as something was worshipping - though he could not think of anyone who had gone down that road (and neither can I, but there is nothing new under the sun).

This was a fascinating thought process, and so although I gave a summary answer on Facebook, I thought I'd do my working out here, for posterity.

My summary answer was:

The Judeo-Christian culture complex of human value is not dichotomic but compatibilistic, and establishes both an intrinsic value to humanity (though being made in the image of God) and instrumental value to humanity (by being instruments of God's glory and grace).
In terms of reconciling this view with God's punishment or threats of punishment against people by killing them, God as Justice and God as Mercy are both more valuable than whatever value human life has. However, humanity does not end at death, because there are post-death eternal consequences to be considered - and a positive eternal consequence is available to humans despite a failure to keep faith/law.

 I think there are two kinds of value involved here. The Judeo-Christian culture complex of  human value derives from humans being made in the image of God. All humans are valuable, regardless of their faith, because they are made in God's image. Insofar as humans are humans, they have this value, and so it is intrinsic to being human.

However, God is a person, who acts with reasons. Two of the reasons given for creating humanity are that glory is given to God (by the act of creating, not necessarily by the humans giving glory through worship), and it expresses God's grace (both insofar as existence is better than non-existence, and also offering the hope of eternal life with God). Insofar as God acted in creating humans with a reason that is beyond humans (because the acts are part of God's nature), there is a level of instrumental value there.

I don't think those two things are dichotomic. Humanity's existence is a means to several ends, but humans also have value because they are made in God's image, and God is Value. So there is no need for a concern about humans being fungible instruments of worship (angels also worship God, but are not made in God's image).

In terms of situations where God kills or punishes people, there are two important points. First of all, God's punishment of people for failure to keep faith/law is not due to a lowering of their instrumental value due to their ability to worship. It is because God is Justice, and the expression of God as justice is more valuable than human value.

Secondly, death is not the end point for humanity: there is an eternity afterwards. Because God is Grace, the expression of God as grace in allowing humans a positive eternal future despite their failure to keep faith/law is also more valuable than human value. So to think of death itself as some sort of termination of human value ignores that human existence does not end at death.