Pope John Paul’s reflections on what he sometimes called “the gospel of the body” unfolded through his Wednesday audiences in St. Peter’s Square, but his teaching was developed in numerous other speeches and addresses, encyclical letters and exhortations on marriage, women and the Blessed Virgin Mary.

It has become increasingly clear that these meditations have the potential to transform our understanding, not only of human sexuality and ethics, but of human nature and culture in general.

It is often assumed that the theology of the body is all about sex. But it is not so simple.

Sexual relations are only a part of something much bigger and deeper. Before we can follow what the Pope is saying about the gospel of the body, we need to understand his method.

It is based on a reading of reality as symbolic, as meaningful, which when applied to ourselves he calls the “language of the body.” The whole world is a book of symbols expressing invisible realities. The language of the sacred Scriptures depends on images and metaphors drawn from this book of nature, and they teach us how to penetrate the language of nature to reach a deeper level of meaning.

Finally, by expressing the fullness of divinity in human nature, Jesus Christ enables us to read the two other books at an even deeper level, seeing in them the “mystery hidden from eternity in God,” which is the mystery of God’s own interior life, into which we ourselves are invited through his death and resurrection and as the body of the Church.

The Pope reads the body in terms of a “spousal” or “nuptial” meaning, which he says has been limited, violated and deformed over time, and by modern culture, until we have almost lost the power of “seeing” it. But it is still there to be discovered with the help of grace, like a spark deep within the human heart. The “language of the body,” therefore, must be recovered, and that is what the Pope seeks to do.

But, as he says, correctly reading this “language” results not so much in a set of statements as in a “way of living” — it is a way of living experienced from within the unity of love.

One of the requirements of this love is purity, the dimension of innocence enabling us to “know” each other (and ourselves) in self-gift. This is a fruit of the Holy Spirit dwelling within the person as in a temple, “the glory of the human body before God” and “the glory of God in the human body, through which masculinity and femininity are manifested.” It is the condition under which the true beauty of the human person can be revealed.

In a way, his teaching on purity brings into focus the Pope’s whole teaching on the gendered body as integral to the human person made in the image and likeness of God and (in that image) made to know God in knowing the Other as the gift of God.

Sin shatters our being into fragments, setting us against ourselves. In a state of sin, having lost my integrity, I am no longer unified enough to be able to give myself as a whole to another. I can only give parts of myself.

It also affects the way I see the world, because the mirror of consciousness in which I see all things is disturbed and shattered, so that I see only fragmentary views of the whole — views of it in relation to the fulfilment of my own desires.

The potential beauty and goodness of human sexuality is clear from the Pope’s writings. But how the full depth of the meaning in masculinity and femininity — including fatherhood and motherhood — would have or could have been revealed in the original state of man he wisely does not speculate.

The real source of gender lies in the nuptial meaning of the body, which will ultimately find fulfilment in the “virginal” state of the world to come.

Therefore, nuptiality affects all of us, whether we are married or not. While I may never be anyone’s spouse, I am always a son or daughter, a sister or brother.

In such ways and combinations of ways, I necessarily participate in the relationship of one gender to another. It is not that, individually, we need to be married in order to be saved, but we do need to play our part in the marriage between Christ and his Church in order to be saved.

Stratford Caldecott is editor of Humanum: Issues in Family, Culture, and Science: A Quarterly Review of the Center for Cultural and Pastoral Research at the Pontifical John Paul II Institute for Studies on Marriage and Family. David Schindler is provost and Gagnon professor of fundamental theology at the institute and author of the forthcoming Ordering Love.