"Secularization, which presents itself in cultures by imposing a world and humanity without reference to Transcendence, is invading every aspect of daily life and developing a mentality in which God is effectively absent, wholly or partially, from human life and awareness."Secularism imprisons the human person within the confines of "the world." Sometimes it restricts itself to the world as human beings immediately perceive it (e.g. materialism). But it can allow for the affirmation of "deeper realities," and for the development of human beings and the universe under the influence of "mysterious" natural powers (e.g. the many kinds of spiritualisms that flourish today, as well as a reductionist view of religion).
Secularism is a proposal of life "without reference to Transcendence." The essence of secularism is its effort to smother the deepest reality in the life of every human person, that thirst for the Infinite that shapes every human heart. The "transcendence" that Pope Benedict speaks of here is not just any kind of "going beyond" the surface of things. It is the Beyond-all-things, that Mystery which energizes the human person and is the ultimate goal of every human aspiration. Secularism seeks to suffocate this "restlessness" of the human heart.
It does not forbid a person to be "religious" (provided that "religion" is reduced to a human system, or a set of rules that rest on human contrivance, whether ancient or new). It does not have a problem with "spirituality" as long as the "spirit" remains in the finite prison of its own idealism, or of the occult. Secularism is even compatible with talk about God. But it wants to eliminate the search for God, the hunger for God, and of course, love for God.
Above all, however, secularism cannot abide the amazing fact that the Transcendent God --the Mystery that every human heart yearns for--has entered history and dwells among us in the very midst of our world. In the end, this is why secularism is doomed to fail: because God wills to make Himself known, because He loves us. He loves every human person, even the most determined secularists who appear to have forgotten all about Him.
The witness to Jesus Christ as God's loving gift of Himself is difficult in our secularized culture. But let us never forget that His grace is at work.