John 8:30

‘As he spoke these things many believed on Him'.

There was something in what Jesus said which, while not fully understood, struck a cord in the hearts of some of His listeners, and they responded in full faith. They ‘believed into him' (eis auton - eis with the accusative), in contrast with the Jews of John 8:31 who ‘had believed in him' (auto - dative case), the latter a faith similar to those in John 2:23 which could not be relied on. His words were thus not totally in vain. This is a typical Johannine contrast.

(The question of what is meant by a ‘believer' is in constant tension in John. Sometimes it means full believers. Those whose response is total. At other times it means those who are ‘won over' by some aspect of His ministry without being actually totally committed. We can rest assured that there were always some of both kinds, just as there are today, and the one often became the other).