Full Idea
In Mosaic theology, man is made in God's image, and so his life is not just valuable, it is sacred.
Gist of Idea
Man's life is sacred, because it is made in God's image
Source
Paul Johnson (The History of the Jews [1987], Pt I)
Book Reference
Johnson,Paul: 'A History of the Jews' [Phoenix 1993], p.34
A Reaction
The obvious question is what exactly is meant by "in God's image". Physically, spiritually, intellectually, morally? I am guessing that the original idea was intellectual, because we are the only rational animal. The others seem unlikely, or arrogant.