Why did the gift of prophets fade away?
The gift of prophets faded away because the printed Word became available. Once Scripture came into print, there was no longer a need for gifted men to speak forth the Word. Apostles likewise faded after the Apostolic Age ended, and prophets were no longer needed.
Les explains from Ephesians 4 that gifted men are given to the Church: apostles, prophets, evangelists, pastors, and teachers. He notes that apostles faded off the scene after the Apostolic Age ended, so we do not have apostles in the Church today. Prophets faded away because we now have the printed Word. Les says that once the Word came into print, there was no longer a need for gifted men to speak forth the Word. Even so, he still lists them in Ephesians. Les then points to where we are today: some evangelists, and some pastors, and teachers.
And he gave some, apostles; and some, prophets; and some, evangelists; and some, pastors and teachers;