Ambrose of Milan

Let us then consider how it happens that the Apostles according to John believed and rejoiced, according to Luke are reproved as unbelieving. John indeed seems to me, as being an Apostle, to have treated of greater and higher things; Luke of those which relate and are close akin to human. The one follows an historic course, the other is content with an abridgment, because it could not be doubted of him, who gives his testimony concerning those things at which he was himself present. And therefore we deem both true. For although at first Luke says that they did not believe, yet he explains that they afterwards did believe.