The word ‘essay’ is a fairly obvious corruption of ‘assay’ meaning ‘trial’. Surely there’s something humorous about using a mispelled word to name an exercise intended to demonstrate the mastery of words and ideas? It’s a particularly English form of humour (in the same vein as persistently spelling the word ‘humour’ with a ‘u’ in the second syllable and refusing to pronounce it).
The Essay is a test put to the student: a challenge to demonstrate mastery of concepts and communication. But within the network of relationships that make up a learning environment, an essay is very rarely ‘just a test’. It is a Trial, an Ordeal – in the old fashioned ‘dunkin’ witches’ sense – something which easily bleeds over the edge of assessing aptitude and becomes intimately bound into revealing identity. Obviously, this is not always the case, and not always the case for every student.
But look at the levels of anxiety that are associated with essays and exams, think about the structures of our ‘meritocratic’ society, our agent-oriented ethical systems, the functionalisation of human relations to each other, the commodification of the world, and tell me that it’s not true.
The Essay is the particular sphere through which a student can be justified by works. The Instituted Order is called upon to examine his or her effort and the extent to which he or she has co-operated with the means of learning (lectures, etc), but ultimately grading must be done against an objective standard and a mark must be given. There are rumours of Academic Saints, those who scored 100% (usually in the more ascetic disciplines like Language), but the taint of sin upon human toil suggests that this must be rare. Perhaps praying for their assistance will bring some relief but, honestly, most of us are just going to have to settle for time in purgatory. 
By the time anyone gets to studying a second degree (like most theological students), they have survived at least 16 years of a graceless education system. Particularly if a student is academically gifted (and not particularly otherwise) then he or she has faced years of reinforcing behaviour that shapes them to live by the approval and acceptance of the gods of learning.
It is a most unevangelical form of education.
Is it any wonder that our theological colleges are full of people who are more deeply trained to seek a secure foundation for identity in results rather than relationships?