The Centrality of the Doctrine of the Trinity according to Bavinck
Now in the confession of the Trinity we hear the heartbeat of the Christian religion: every error results from, or upon deeper reflection is traceable to, a departure in the doctrine of the Trinity. . . . To the church the doctrine of the Trinity was the dogma and hence the mystery par excellence. The essence of Christianity – the absolute self-revelation of God in the person of Christ and the absolute self-communication of God in the Holy Spirit – could only be maintained, the church believed, if it had its foundation and first principle in the ontological Trinity.
-Herman Bavinck, Reformed Dogmatics, vol. 2, p.288, 296
The rest of his discussion on the Trinity is excellent. It’s definitely worth the read!