The noted Swiss theologian, Emil Brunner, wrote in his book, The Mediator: A Study of the Central Doctrine of the Christian Faith, of the absolute necessity of keeping our mediator, Jesus, at the very heart of Christianity:

In Christianity faith in the Mediator is not something optional, not something about which, in the last resort, it is possible to hold different opinions, if we are only united on the 'main point'. For faith in the Mediator – in the event which took place once for all, a revealed atonement – is the Christian religion itself; it is the 'main point'; it is not something alongside of the centre; it is the substance and kernel, not the husk. This is so true that we may even say: in distinction from all other forms of religion, the Christian religion is faith in the one Mediator... And there is no other possibility of being a Christian than through faith in that which took place once for all, revelation and atonement through the Mediator.