Reprising here an excerpt from a Bavarian Radio address from Fr. Joseph Ratzinger in 1986.
That is what distinguishes the Christian—that he has received a tongue of fire in addition to his human nature. That is how the Church came into being. Each person receives the tongue of fire that is wholly and personally his and, as this person, he is a Christian in a unique and inimitable way.
Admittedly, one who encounters the average Christian today is likely to inquire: “But where, then, is the tongue of fire?” The words spoken by Christian tongues today are unfortunately anything but fire. They taste all too much like water that has been left standing and is barely lukewarm, neither hot nor cold. We have no desire to burn either ourselves or others, but in not doing so we place ourselves at a distance from the Holy Spirit and our Christian Faith degenerates into a self-made philosophy of life that wants to disturb as few people as possible out of our comfortable habits and relegates the sharpness of protest to a place where it can cause the least inconvenience to our customary way of life.
If we elude the burning fire of the Holy Spirit, it is only at first glance that being Christian seems easy for us. What is comfortable for the individual is uncomfortable for the whole. Where we no longer expose ourselves to God’s fire, the frictions among us become insupportable and the Church… is torn by the cries of interior factionalism. Only when we are not afraid of the tongues of fire or of the strong wind that accompanies them does the Church become an icon of the Holy Spirit. And only then does she open the world to the light of God.
The Church had her origin when the disciples gathered with one mind in the room where they celebrated the last supper and prayed there together. It is thus that she begins over and over again....
