Why I Am Not a Christian?

Bertrand Russell is no doubt a great thinker and one of the better ones of our time. Though there are some inconsistencies in his thought process (who doesn't have them with so many topics and points of views, etc.) which I was curious about, and more so I was wondering if anyone else could have some explanations to my doubts.

In the fourth argument which he wishes to debunk is the Moral Argument for Diety. He states among his thoughts, and this one being the most logical I believe, that good and bad exist, therefore a higher being had to put them here. Therefore, good and bad have to be apart from who God is, meaning that God is not good. My rebuttal would be to argue that if God himself is good, in his essence (which many religions claim), that which is not of him would therefore be bad. His very existence would be the definer of what is good and bad, therefore good, bad, and God all exist and coincide.

My second rebuttal, or skepticism it could be said, is on the Remedying of Injustice, the fifth argument Mr. Russell argues against. My argument is more towards what most evolutionist and scientist claim, that religion is not necessary for morals, because morals are/can be/have been developed through the evolutionary chain. If injustices are a part of the universe as Bertrand Russell leads us to believe with the example of the crate of oranges in his rebuttal against the necessity of God to remedy injustice, then injustices are simply a part of what has come about through evolution so that each of us can assure our own good, our own survival. Only the fittest will survive no matter the cost, right? We do not call it injustice that an octopus devours a crab or that a lion easily hunts down a zebra. We call it nature and natural. But when a person cheats or does some type of injustice (based on our basic human moral code) we see that as not right...unjust. How can we have morals that come from science and evolution, and also have injustices as a natural part of our world? The two ideas seem to contradict.

Again these are my thoughts and rebuttals, and I ask and welcome from everyone the answers to these questions.