Reflecting back on the first time he was called upon to officiate at mass as a young priest, Luther wrote:
When I stood there during the mass and began the canon, I was so frightened that I would have fled if I hadn't been admonished by the prior. For when I read the words, 'Thee, therefore, most merciful Father,' and thought I had to speak to God without a Mediator, I felt like fleeing from the world like Judas. Who can bear the majesty of God without Christ as Mediator? In short, as a monk I experienced such horrors; I had to experience them before I could fight them.
--Martin Luther, 'Table Talk,' in LW 54:234