Rivers of medieval ink, not to mention...

Rivers of medieval ink, not to mention blood, have been squandered over the ‘mystery’ of the Trinity, and in suppressing deviations such as the Arian heresy. Arius of Alexandria, in the fourth century AD, denied that Jesus was (i.e. of the same substance or essence) with God. What on earth could that possible mean, you are probably asking? Substance? What ‘substance’? What exactly do you mean by ‘essence’? ‘Very little’ seems the only reasonable reply. Yet the controversy split Christendom down the middle for a century, and the Emperor Constantine order that all copies of Arius’ book should be burned. Splitting Christendom by splitting hairs – such has ever been the way of theology.