Religion is in a state of progressive revelation. Religious truth is relative truth.
The Bible should be respected just as you respect your 90 year old grandfather who is becoming senile. Countless millions died in their age for a form of these beliefs. Humanity is like raising a child, in the Bible age, when the Bible was the authoritative word, humanity could be said to be childlike. Science and understanding were in their infancy.
The Bible doesn't work today because it has passed its used by date and it simply does not have teachings that can deal with the complexity of this modern world. There are new and far more lethal problems that we are beset by. The Bible and other works laid down a matrix of moral codes and behavioural axioms.
As far as the violence goes in the OT, this is not Christianity, this is a completely separate religion no closer to Christianity than Islam. The violence reflects its zeitgeist, religion always reflects the national zeitgeist.
The errors from OT to NT are because they are different religions from different ages. From within the NT itself, especially the 4 gospels, they are collections of liturgies. They are transcribed sermon teachings that have drifted in context from teacher to teacher. The general themes of morality and virtues remain pretty much in tact but the nonessential doctrine has wandered about a bit. This is a product of the age and the drift in oral accounts which is unavoidable in such an age.
