Every ethic is connected with an assumed anthropology and worldview. We instinctively act out of a sense of who we are, and our place in the world.
Our answers to the questions “Who am I?” and “What am I?” are intimately connected to the question of “How ought I to be in the world?” In other words, theological anthropology can never be entirely descriptive. A description of human nature always both presumes and entails a prescription for human living. [Marc Cortez, Theological Anthropology: A Guide for the Perplexed: 2-3, emphasis in original]
Christian ethics are theological, evangelical and scriptural. As Christians, we conduct all of life coram Deo: God is the ultimate reality, the foundation and framework of the world we operate in, in whom all things hold together. We think of ourselves as beings created by God, beloved by him, and responsible to him. This God we worship is not distant and unknowable, but is God in Christ. The cosmos is Christ-powered; it does not operate purely through natural processes or human agency [Andrew Cameron, Joined-Up Life: 84-86].
Christian ethics are theological through being Christological. We can know God because he has revealed himself in his Son. And our knowledge of God’s Son, the man Jesus Christ, is shaped by our knowledge of his historical work for us: his incarnation, ministry, death, resurrection, heavenly session, and expected return – we know Christ through the gospel. And we know the gospel through the scriptures – the Old Testament which prophecies him, and the New which demonstrates the fulfilment of the prophecies, and explains his significance for his new people – the international church.
The Bible makes a very radical idea inescapable: not only in the gospel the interpretative norm for the whole Bible, but there is an important sense in which Jesus Christ is the mediator of the meaning of everything that exists. In other words, the gospel is the hermeneutical norm for the whole of reality. [Graeme Goldsworthy, Gospel-Centred Hermeneutics: 63, emphasis in original.]
Thus are Christian ethics theological, evangelical and scriptural. Through the bible, we know Christ, who brings us to God. And, through this knowledge of God, we know our world and ourselves.
Nearly all the [true and sound] wisdom we possess… consists of two parts: the knowledge of God and of ourselves. [John Calvin, Institutes, 1.1.1]