The doctrine of the Trinity can be regarded as the outcome of a process of sustained and critical reflection on the pattern of divine activity revealed in Scripture, and continued in Christian experience. This is not to say that Scripture contains a doctrine of the Trinity; rather, Scripture bears witness to a God who demands to be understood in a Trinitarian manner.
–Alister McGrath, An Introduction to Christianity (Cambridge, Mass: Blackwell, 1997), 193.
Reflections 