Crossway publishers has put up a great excerpt from Graham Cole’s forthcoming book Faithful Theology. Here’s a gem quote:
Why does doctrine matter? The importance of doctrine lies in that it answers three normative questions vital to us all: (1) What ought we to believe (orthodoxy, right opinion)? This is the truth question. (2) What ought we to value (orthokardia, right-heartedness)? This is the spirituality question. (3) How ought we to live (orthopraxy, right practice of life)? This is the existential or practical question. Put another way, the head (orthodoxy), the heart (orthokardia), and the hands (orthopraxy) all count as concerns of theology. For example, what ought we to believe about the identity of Jesus? Does our answer matter? How are we to live in the light of Jesus’s identity? If you believed, as many do, that Jesus was merely human, then worshiping him would be idolatry. But if Jesus is a member of the Holy Trinity, then worship is entirely fitting.