Trinität und der Ursprung der Gemeinschaft

The doctrine of the Trinity is the gateway to understanding Christian life. A God who was completely alone would have had nothing relational to offer us in salvation; he could have offered only a right status before him or something of the sort. But because God has eternally existed in a fellowship of three persons, there is fellowship within God in which we can also share.

Donald Fairbairn, Life in the Trinity, IVP: Nottingham 2009.