Here I’ll be quoting from a genius in the reformed community, Dr. Vern Poythress. The quote comes from his book “Redeeming philosophy” . Which there is free  PDF here : http://frame-poythress.org/ebooks/

“Perspectives on Ethics
If metaphysics is multiperspectival, so is ethics. John Frame’s work on ethics supplies us with resources. His book The Doctrine of the Christian Life has addressed extensively the area of ethics, including philosophical ethics. The book interacts with and criticizes major systems of philosophical ethics, namely, deontological
ethics, utilitarian ethics, and existentialist ethics.In addressing these questions, Frame’s book relies on the Bible throughout. Using the Bible, Frame is able to give straightforward, biblically based answers. God is the Lord of all. His absoluteness, his goodness, and his justice together are the ultimate source for moral standards. Human beings are made in his image, and so, by God’s plan, they have in their consciences a sense of moral right and wrong. Since the fall into sin,this sense can be and is perverted, buried, and otherwise evaded. But it is still there. God also rules history, so that morally good or bad behavior has consequences. Because God designed us,he knows what is best for us.True moral standards are found in what God commands in the Bible. Since God is the ultimate authority for moral standards,he provides the norms for ethics in his word. The character of God as our ultimate authority provides the foundation for the normative perspective. God’s word provides abundant instruction, so that we need not remain in doubt about answers to fundamental ethical questions, such as whether stealing is wrong and why. We know that stealing is wrong because God says so. And we know why it is wrong because it violates God’s commandment not to steal. Since God created the world and rules over it, he also provides the situation in which we live. God therefore provides a foundation for the situational perspective, which focuses on the circumstances around us. From a situational perspective, we can give additional reasons why it makes sense that stealing is wrong. God created a world in which obedience to his commandments leads to blessing. An individual who refrains from stealing escapes the liability for stealing;he escapes a guilty conscience; and he escapes punishment that he will receive if he is caught (or punishment in the next life even if he is not caught in this life). Not only the individual but the society benefits. A society whose members refrain from stealing avoids anger and quarreling and bad feelings and destruction of property and other consequences that stealing tends to produce. Such a society flourishes, and the people in it flourish. They receive blessings from God, both directly in a sense of his pleasure and indirectly through additional material prosperity. Finally, God created us as human beings, who have a conscience and a sense of right and wrong. God thus provides the foundation for the existential perspective. This perspective alerts us to further reasons why theft is wrong. It is wrong because our consciences tell us it is wrong. Of course, our consciences may be
corrupted by sin, so they do not provide an ultimate authority. The ultimate authority belongs to God. A Christian existential perspective is able to explain how people’s internal sense of right and wrong contributes to ethics. At the same time, it avoids re-
ducing ethics to the standards of human conscience, which would lead to relativism. In sum, Frame’s three perspectives for ethics—the normative, situational, and existential perspectives—work together because they harmonize according to God’s plan. God ordained all three of them through his control over the norms, the situations, and the human persons. He also gave us the capacity, as human beings, of thinking about and appreciating all three perspectives. We can do so because God made us in his image.The three perspectives harmonize if we use them properly, in communion with God and with an appreciation for the way in which God designed them to interlock.Within a biblically based approach, these three are perspectives on the same whole. Each leads to the others. Each implies the others and each presupposes the others.

Non-Christian Ethics:
By contrast, secular philosophical ethics has found itself in conundrums. Deontological ethics is a kind of secular version of the normative perspective. It focuses on transcendent norms for ethical behavior. One such norm might be that you should do to others as you want them to do to you. For example, you should not steal
because you do not want others to steal from you. But when this perspective is detached from God who gave it, its connection with human persons and with the existential perspective tends to disintegrate. Why do we as humans have any connection with these alleged norms? Why should I commit myself to the principle of not stealing, or the more general principle of doing to others what I want done to me? Why not rather be selfish? Why not steal as long as I can get away with it? And if someone else steals from me, why not go after him out of selfishness, rather than out of a general principle that theft is wrong? And why should we think that the norms have any connection with our situation? Utilitarian ethics (and more broadly teleological ethics, that is, ethics based on goals) is a kind of secularized distortion of the
situational perspective. Utilitarian ethics says that we ought to maximize “utility,” the sum of benefits for all human beings. But how do we measure utility without norms for measurement? In secular utilitarian ethics, the situation gets isolated from the
norms, so that we can always ask, Why should I care about maximizing utility?
Utility has no deontological or normative “bite” to it. For example, it might be argued that a poor person should be allowed to steal from a rich person because the poor person has more need for the money than the rich one does. Indeed, some people are in favor of schemes for “leveling the wealth.” But other people would object that the relative need that a poor person has does not make it right for him to steal. They are thereby calling in question whether utilitarian ethics (or at least this form of utilitarian ethics) is right. Similarly, teleological ethics says that we should choose our actions so that they lead to the best goals, the best outcomes. But who decides what outcomes are “best”? And without existentially oriented wisdom, how can a human being judge well which actions lead to which goals? Political ethics in particular is plagued by what has been called the “law of unintended consequences.” Laws that politicians put in place with good intentions have unintended consequences. For example, a law reduces the speed limit to promote safety, but it results in people wasting more time in traveling. A law puts in place standards for state-controlled education, but the law frustrates good teachers who want to teach for long-run understanding rather than merely for ability to do well on a standardized test. A law for rent control forbids landlords from increasing the monthly rent, in order to protect the renters. But the landlords, finding that rising prices gradually leave them with an unprofitable business, refuse to maintain and repair their rental properties. The renters do not suffer from higher rents but end up suffering from poor living conditions.
Finally, secular existentialist ethics is a distortion of the existential perspective. Secular existentialist ethics starts with the individual. And since it does not acknowledge God, the individual must himself generate his own ethical norms. He creates his own
meanings. Here the existentialist idea of creating one’s own life detaches existentially created meaning from external norms and from the situation. By contrast, Frame’s Christian approach has all three perspectives. They harmonize because one God promulgates the norms, creates the world, and creates human beings with a sense of morality. Frame also can contribute to resolving many other specialized ethical issues because the Bible is such a rich source of ethical instruction, both directly through commandments and indirectly through illustrations in its historical portions, as well as the rich knowledge of God that it promotes. Its principles have implications for the ethics of war, abortion, poverty, child rearing, state-controlled education, marriage and sexual relationships, and more. In the study of the Bible itself, we see a kind of interaction between the three perspectives. The commandments are in focus
in the normative perspective. The historical portions are in focus in the situational perspective, which helps us grow in understanding how situations call for embodiment of ethical principles. God himself as a personal God is in focus in the existential perspective,which leads to focusing not only on human persons and their motives, but also on God as a divine personal God, whose character is both source for our norms and motivation for our activity.” Pages 189-194