Jacob's discussion of the judgement is interesting for the way in which the judgement occurs. In verse 14, Jacob indicates that before the official judgement comes that there will be a natural division between the unrepentant and the righteous.
In the first phrase, Jacob uses the collective "we" as a device to include himself with others in the audience among those that will "have a perfect knowledge of all our guilt." Nevertheless, this is a device only, one inserted for the demonstration of humility, for surely Jacob would (and knew he would) fall into his second category, that of the righteous that "shall have a perfect knowledge of their enjoyment."
In Jacob's developing theme, verse 14 set up the continuation and perfection of knowledge after death. He indicates that there is a self-consciousness, a self-understanding that we have here, and that it shall be with us after death. The difference is that after death that knowledge will be perfect (verse 13). This perfect self-knowledge will allow us to see ourselves with the eyes of deity, and we will understand our relative position to our God. We will see ourselves as either full of guilt, or "being clothed with purity."