Good, bad and the ugly

Although I feel my actions are "good", I don't hold "good" and "bad" are moral standards. Everything that one does is both beneficial and detrimental at the same time. I may buy a loaf of bread for a poor family, but that loaf was made by growing and then killing yeast; it was likely delivered to the store in a truck that consumed fossil fuel that polluted the atmosphere; it was packaged in plastic, also from fossil fuel, that when discarded will be garbage polluting the Earth. Here's a more basic example: every breath we take adds a few seconds to our life, but also takes us one breath closer to our last.Something good is something we perceived as more beneficial than detrimental; and visa versa for something that is bad. So, from this, how does one presume a moral code? "Experience" is often sited. However, since everything is relative to one's prespective, how is society supposed to trust each individual's experience to steer them towards activities which it feels are more beneficial than detrimental?Once we answer that, then we can toss out religion. Any takers?
For me, my morality is based on my experiences. I do try to have all of my actions within what is preceived as being "good" (more beneficial than detrimental). Is there any way for society to codify this? Yes, through secular law. Of course, then one can get into the duscussion about fairness of certain laws, but that's another topic all together.