on one hand it means that the Lord indeed will hold accountable the life of every man from his fellow humanbeing, his brother who have taken his life in murder, having blood in ones hand means to have killed. the life of man or animal is linked with blood so our life is linked with the life of our brother.
the Lord will ask where is thy brother, and the answer better not be a haughty ' am I my brother's keeper?!'
blood is spilled in many ways, through active participation, through neglect, through indifference, through indirect participation. the Lord will take all those into account and seeks the life of our brothers from our hands.
Love thy neighbor as yourself, you are your brother's keeper! and your brother is the least one among us all. it is him that the Lord will defend on that day, it is him the Lord will vindicate, it is him the Lord will remember in His Kingdom and will ask you and me about. what have we done with our brother the least among all these?
your brother that was sick, that was poor, hungry, naked, imprisoned, the outcast and the stranger, the alien in your cities, what have you done to him?
our life is that much linked with the life of our brother...The Lord is compassionate and holy , he loves his creatures and would have the even the beasts' lives to be honored and our relationship with them should be one of reverence and love even while we use them for their permitted purpose. eat their flesh, but their blood you should not eat, its desecration of God's creatures. and for our treatment of the created world and the creatures there in, entrusted to us by our priesthood as children of Adam, we will be held accountable for all the cruelty and selfish destruction we have caused them our fellow citizens of the world.