I don't exactly know what you mean by the value of life. But if you mean what are we put on this earth to do then I have something to say about that. We are put on this Earth to honor and glorify God. That's why we were created. We were created to live for God and to keep his commandments, and live for his glory and happiness. You can agree or disagree but that's what I think and believe! If you don't know by now I'm a Christian
Having faith in something is always a good way to justify value of life. People want to have a reason to live and most resort to Religion.
Value of life can and is different for many people as we are all unique. It really just depends on the person I guess.