The birth of Christ is the eucatastrophe* of Man's history. The Resurrection is the eucatastrophe of the story of incarnation.
This story begins and ends in joy. It has pre-eminently the 'inner consistency of reality'.
There is no tale ever told that men would rather find was true, and none which so many sceptical men have accepted as true on its own merits.
For the Art of it has the supremely convincing tone of primary art, that is, of Creation.
To reject it leads either to sadness or to wrath.
From the Epilogue to On Fairy Stories by JRR Tolkien
Until a person has understood in his heart the validity of what Tolkien wrote above with no tale ever told that men would rather find was true; he has not understood Christianity - and does not know what he rejects, or accepts.
*A sudden and favourable resolution of events in a story; a happy ending