Herman Bavinck, one of the greatest theologians of the 20th century (and certainly my favourite), on the Trinity:

"The thoughtful person places the doctrine of the Trinity in the very center of the full-orbed life of nature and mankind. The mind of the Christian is not satisfied until every form of existence has been referred to the triune God and until the confession of the Trinity has received the place of prominence in our thought and life."

Because, Bavinck argues, the Trinity is so absolutely central to Christianity, it is not surprising that he would elsewhere say this:

"Every error results from, or upon deeper reflection is traceable to, a departure in the doctrine of the Trinity."

We simply cannot afford to let the doctrine of the Trinity become something secondary or inconsequential. Everything – our life, or worship, or doctrine – must reflect the fact that at the very core of the Christian religion is the triune God.