I believe that humans can discover truth (not invent it). Since a profound sensibility and awareness of something that feels like objective morality is found in nearly every known person and society throughout history, it is reasonable to conclude that this orientation is part of nature/biology. Whether or not God exists or has implemented this ethical system upon and intrinsically within the cosmos is another issue entirely.
It may be possible that spiritual and moral laws are analogous to physical laws. When I use the term “spiritual law”, I don’t specifically include miracles in the meaning. Miracles in a theological sense are out of the ordinary happenings that God directly causes, as opposed the normative physics of nature (which encompasses all that God made, like what we call the empirical world and other dimensions where angels/demons/heaven might exist). In the Bible, there is a strongly implied connection and continuity in the general operational functionality between all realms of reality, whether in the Garden of Eden, this life or the afterlife. Some or many specifics may change, but the essential elements remain intact (such as what it means to be human through having some type of physical body, free choices with resulting consequences from our thoughts/intentions/actions, opportunities to learn/grow, etc.). I think that all aspects, visible or invisible, of the cosmos (or creation) are interrelated by necessity. In religious traditions such as Christianity, the teachings repeatedly use natural phenomenon to illustrate spiritual principles. Jesus’ parables are based on “earthly” situations that correspond to ultimate transcendent truths. Further, many Christian evangelistic methods appeal to a supposedly analogous relationship between physical and spiritual laws.
The main argument I hear often from Christian apologists is that there can be no objective morality without a supreme and personal law giver, such as God. I’m open to changing my position, but I don’t see why a transcendent god must be required to create or maintain the apparatuses to encompass cycles of cause/effect (whether moral, spiritual or physical). If there is an afterlife, this too doesn’t require a deity in order to have resulting moral, spiritual or physical conditions that correspond with and follow the patterns begun in an earlier period of human existence. In what has historically been a general human perception: life is short, messy and imperfect – so “justice” may not happen in this stage of being. An afterlife awaiting humans could provide opportunities for them to receive even more layers of consequences and personality/aptitude/character development, both good and bad, entropic and generative, healthy and unhealthy, depending on what is inevitable, deserved and graceful (since existence in this universe often allows for multiple possibilities within a sphere of limited freedom, even when it appears that we have exhausted all options and reached a dead end). In this case, the Moral Law Giver and Ultimate Judge could be the unconscious universe itself (whether these aspects of reality are inherently connected with and dependent upon God or not – contrary to orthodox Christian belief, a deist or a panentheist god might exist).
I think the point of exploration toward (hopefully) more accurate understanding of these realities is to let the evidence speak for itself, whether or not we can make full sense of it. If what we interpret and discover is incomplete, then so be it. There’s no immediate reason for someone to jump to an absolute or cosmic conclusion or chose to follow the Judeo-Christian or any other faith or philosophy as a default position (like a “God of the gaps” type of response). Though the psychological tendency of humanity to desperately seek existential and physical security may be dominant, it’s worthwhile to resist a premature commitment in thought or lifestyle. I recognize that we must make intellectual and volitional decisions on a daily basis (as a matter of practicality) – yet this can be done with a sense of humility and willingness to change when new evidence presents itself or entices us to look further down familiar or personally uncharted paths.
[For more on this type of thinking, I commend to you my second favorite book of all time, Apology For Wonder by Sam Keen. He covers many important things here on how to strive toward having a honest, comprehensive and effective theology/philosophy of life within the Christian tradition generally (given modern/post-modern existential concerns), including how to possibly find a naturalistic foundation for what the Christian tradition calls “grace” or “unmerited favor”. My favorite book is Original Blessing: A Primer in Creation Spirituality by Matthew Fox.]
Regarding the project of trying to find a purely scientific basis for morality, I appreciate the initial efforts by Sam Harris’ book, The Moral Landscape: How Science Can Determine Human Values (or video), and Michael Shermer’s text, The Science of Good and Evil: Why People Cheat, Gossip, Care, Share, and Follow the Golden Rule (or video).
To those people who say that a transcendent Christian god is necessary for objective morality, I have written a blog post to show that any god, especially the divine character from the Bible, who might have designed this universe, could not have any moral high ground or valid right to judge human beings. Nature is too full of destruction, waste and suffering (both for non-human animals and humans). The biblical narratives, though they contain many positive and insightful teachings/principles, are overly packed with inhumane actions by God and encouragements or commands for righteous humans to follow in His/Her example.
I agree that many humanist ideas come from Christianity, but they also are based on Greco-Roman traditions and some general human intuitions. I think that the insights from Christianity and all other religions/philosophies/spiritualities belong to humanity as a whole. There is no reason to hold on to traditional religions as fully operating institutions, especially when it’s clear that society can and has maintained the benefits of humane principles without a religious foundation. Secularization of religious teachings are fine as long as they work (and it’s furthermore helpful for people acknowledge where the ideas came from originally). Modern thinking has discarded many destructive teachings from the Bible and this is a good thing.
Many conservative Christians have told me something like that “the whole notion of equal innate human rights is very difficult to justify without a high view of the sanctity of human life, which you certainly don’t get from materialism”. I partly agree in that it is hard to argue for transcendent ethics without supernaturalism. But, transcendent ethics might not be necessary, especially given that modern society is far more productive, healthy and peaceful than pre-modern Christian culture was. Today among Western nations and individual states within the U.S., those which are the most conservative and religious are the most violent and plagued with far greater social problems related to overall crime, economic mobility, infant mortality, environmental abuse, teen pregnancy, incarceration, life expectancy, poor educational systems, murder, healthcare efficiency, business opportunities, average worker to CEO pay ratio, paid maternity leave, obesity, income inequality and minimal worker’s benefits.
The moral instinctual pattern in all known people groups does not clearly link itself to transcendent morality. Given the great variety (and many times contradictory nature) of moral systems and the fact that other types of apes and dozens of other species categories demonstrate compassionate tendencies outside their nuclear family along with behavior analogous to varying degrees to that of humanity regarding guilt, shame, pride, love, sorrow, depression, fear, dread, etc., a natural basis for morality is easily explainable apart from a transcendent source.
During various points in modern history, when people (including those of marginalized groups) have felt free and safe enough to speak their minds about what a fair and ideal world would look like, they have most often said that they desire a society that provides opportunities for life, liberty and the pursuit of happiness, much like that of the type of Enlightenment humanism (partly evolved from Christianity) that supports the philosophical foundations of the United States Constitution, Declaration of Human Rights, Geneva Conventions, Unitarian Universalism and United Nations. Why isn’t that enough? If the golden rule can be generally appreciated and the avoidance of severe pain and trouble be fixed as a utilitarian goal for society, and the results of this type of morality and sociology have been working so progressively well for the past 300 years, why go back to a traditional religious worldview?