John 16:31 - Ellicott's Commentary On The Whole Bible

Jesus answered them, Do ye now believe. — Comp. Note on John 1:50. Here, as there, the words do not necessarily ask a question; and, although many expositors prefer to take them interrogatively, a sense more in harmony with the context is got by understanding them as an assertion. Our Lord did not doubt their present faith (John 17:8); but He knew that the hour of their full illumination had not yet come, firmly as they believed it had. Their present light was as the flash of the meteor — brilliant, but passing away. The clear and steadfast light of day was in the future, of which He has spoken to them. They think the hour of full knowledge has come. He sees the time when they shall all be scattered and leave Him alone, close at hand. It is this thought which He expresses to them — “Now ye do believe: Behold, the hour cometh...”