Prisoner's dilemma

I was told about a book called "Practical Ethics" by Peter Singer, and read Wikipedia's summary today. There are quite a number of points which I cannot agree with him, especially seeing "love your neighbor like yourselves" as weighing the interests of others equally as oneself, and therefore ending at an criterion function that maximizes the overall benefits. The biblical interpretation of this verse must be "sacrificial". Yet, you are not asked to sacrifice in every situation for nothing. This was what the popular Pastor Lam from HK said, "only an action with a good intent and a good consequence is from God for He is both love and wisdom". Of course, we have different standard of what is good. Now I understand why a Christian world-view and an atheist's world-view do not reconcile.