Most scholars assign all John’s writings to AD 90-95. The basis of their view relies on ambiguous early writings of the Church Fathers and legend. In my opinion, the pre-AD 70 date can be substantiated from within the Gospel itself.
Joh 5:2 KJV Now there is at Jerusalem by the sheep market a pool, which is called in the Hebrew tongue Bethesda, having five porches.
The porches were destroyed in AD 70.
John Wesley wrote, ‘There is in Jerusalem – Hence it appears, that St. John wrote his Gospel before Jerusalem was destroyed: it is supposed about thirty years after the ascension…’
John A T Robinson (1919-1983) was also puzzled that ‘…one of the oddest facts about the New Testament is that what on any showing would appear to be the single most datable and climactic event of the period – the fall of Jerusalem in 70 AD, and with it the collapse of institutional Judaism based on the Temple – is never once mentioned as a past fact.’
I recently stumbled upon a fascinating archeological article on the subject of John’s Gospel with reference to the Pool of Bethesda. Although, it is safe to say it wasn’t written in defence of Preterism, it is a ‘must read’ for Preterists.
Jerusalem Finds Validating the Gospel of John by John Black.
Alexander Gibb