Ratzinger explains in depth the concepts of faith and communion with God. He explains that what cannot be seen by humans is reality. He says that this idea is what gives people the ability to exist. The core of human existence does not rely on the tangible; instead, it is the intangible that is of importance. God cannot be physically seen, but it is God who creates human life and without him, people would not exist.
Furthermore, with the issue of faith arises the concept of doubt. Ratzinger claims that doubt is inevitable. Even someone who strongly believes in Christianity will doubt those beliefs. At the same time, though, the person who does not believe in the tenets of Christianity will question that nonbelief, wondering if maybe there is a reason to believe. In this sense, the believer and the nonbeliever are connected in that they both doubt their beliefs. Even the nonbeliever’s choosing not to believe in Christianity is a belief of sorts.
As for those who do believe in Christianity, it is important for them to understand how faith is a dialogue. Ratzinger states, “The Creed is a formula that forms the residue of the original dialogue: ’Do you believe—I do believe.’” Essentially, it is a conversation in which a person hears, receives, and answers. This idea is the opposite from philosophy, where the person uses thought to reflect on a certain concept and then that person puts that concept into words. Faith, though, is not something that arrives because of a person’s thoughts. It comes from outside the person. In the case of Christianity, it comes from God and is followed by the individual answers.
More than one human being experiences this dialogue or conversation with God. According to Ratzinger, the relationship one individual has with God cannot be separated from the fellowship that individual has with other people. This is why the establishment of the Church is so important to Christianity. It is worshiping as a community that allows this dialogue with God to take place. Ratzinger explains that God’s conversation with humans work through the interactions people have with one another. If people do not worship God as a community, then this contact with others will fail to take place.