Christ is known as an event of history. He stands before us face to face. It is someone who does not identify with my own "I", or with some collective "we", just as each of us does not identify with the "I" of someone else. Christ therefore - not in every way, but in some way - is "outside" for us. Our knowledge of Him is knowledge that can be compared to the knowledge we gain from any other event in History. We can distance ourselves from Him. We can accept Him as our God or reject Him. We can believe His words or disbelieve them. We can love Him or dislike Him.

It is not the same, however, with the Holy Spirit, because the Holy Spirit is perceived by us only within our empirical sphere, in the same way that the wind is a certainty of our experience, not a certainty of objective knowledge.
Therefore, our only knowledge of the Holy Spirit is experience. And perhaps this is why Mark's gospel states that, although any blasphemy against Christ can be forgiven, blasphemy against the Holy Spirit is not. Christ can be misinterpreted. We may not recognize Him. We may misjudge. But we cannot deny some of our experience that is connected with the Holy Spirit, because it is our own experience.