If there is no absolute good then what human life is based upon?

How can you possibly define absolute in any context? It's just a convenient term. You seem to seek explanations where there are none. Most of us are content to work our way through life doing our best without needing to examine the meaning of life. If you are tortured by such matters, which you appear to be, try meditation or take up a hobby. Better still join the Salvation Army and help the needy.