Affirming the absolute need for personal regeneration is the sine qua non of historic evangelicalism. Affirming that the gates of hell will not prevail against the Church is the sine qua non of historic catholicity. Deny the former only, and the end result is the deadly nominalism found in many quarters of the institutional Church. Such saintlings need to be told that God can make sons of Abraham out of rocks. Deny the latter only, and you have the endless splintering sectarianism that has come to characterize American pop evangelicalism. This comes about when Christians cease affirming the need for an invisible work of the Spirit of God, and presume to be able to see exactly how and when that regeneration happens.
But the moment of regeneration is never visible to us. Lack of regeneration, however, is visible over time because the works of the flesh, Paul tells us, are manifest. And the fruit of the Spirit manifest themselves publicly as well, and Jesus tells us to make our judgments on the basis of fruit. But it must be noted that biblical judgments of this sort are mature, and are based on the mature outcome of a person’s way of life. All this to say that genuine discernment is based on the video, not on the snapshot.