John Paul II, in his encyclical Evangelium vitae (1995), takes seriously the statement in St. John's Gospel that life is something divine in the strong sense, an attribute of the divine being: "In him [the Word=the Son of God] was life, and the life was the light of men. And the light shines in the darkness, and the darkness did not receive it" (Jn 1:4-5).

In this text, the notion of life is attributed to God. When we speak of divine or supernatural life, we do not do so in a merely metaphorical sense. It would be so if human life could be explained simply from below, from its genesis and its material past. In that case the life we receive "from above" and "from below," which the biblical Greek calls respectively "zoë" and "bios," would designate two opposite realities. But it is significant, says Spaemann, that these two concepts [which, as used by St. John, express different attitudes towards life] have been translated into other languages (Latin, Romance, Germanic and Slavic languages) with the same term: life.

Indeed, in biblical usage, "zoé" is life in general as a gift of God, who wanted to create living beings such as people and animals or plants.

"Bios," on the other hand, is used to signify the duration of earthly life, the means that sustain it or the manner in which it is lived; it is therefore only used at reference letter to human beings and above all with a rather negative sense, indicating a life with one's back turned to God. This is how it is used in the New Testament. To limit ourselves to the writings of St. John, he uses "bios" (1 Jn 2:16 and 1 Jn 3:17) to express a purely earthly existence apart from God; but he uses "zoé" many times (cf. Jn 1:4; 3:14-16; 6:48; 10:1; 11:25; 14:6, etc.) to explain life according to God, as a participation in the divine life.

To put it briefly: for St. John, life is, above all and simply, something divine, transcendent; and, therefore, it is neither fully realized nor fully understood without God; in any case, it is a divine gift. In this perspective, whoever lives apart from God does not really live a true life.

Along these lines, the encyclical takes up this quotation of Dionysius the Pseudo-Reopagite, a Christian-Byzantine theologian of the 5th-6th centuries:

 "Let us now celebrate the eternal Life, source of all life. From it and through it, it extends to all beings who in some way participate in life, and in a suitable way to each one of them. The divine Life is itself vivifying and creative of life. All life and all vital motion proceed from Life, which is above all life and above the principle of life. From this Life comes to the souls to be immortal, and thanks to it every living being lives, plants and animals up to the Degree smallest of life. Moreover, it gives to men, in spite of being composed, a life similar, as far as possible, to that of the angels. By the abundance of his goodness, he attracts and directs us, who are separated. And what is still more wonderful: he promises that he will transfer us integrally, that is, soul and body, to the perfect and immortal life. It is not enough to say that this Life is living, but that it is the Principle of life, the unique Cause and Foundation of life. It is fitting, therefore, for all life to contemplate it and to praise it: it is Life that vivifies all life" (emphasis added).

Robert Spaemann underlines in his lecture on Evangelium vitae (Pontifical Academy of Life, 14-II-2000), that the divine life is not called "life" in a metaphorical sense dependent on "our experience" of human life. It is rather the case that for St. John divine life is thefirst reference letter in a descending line of analogates (the element on which all depend or to which all refer is called the principal analogate in a comparison). In the sequence of living beings, plant life is the "weakest echo" and, therefore, the least accessible to us.

In contrast to the current scientific view according to which what we understand best are the lower forms of life and worst ourselves, Spaemann observes that what Heidegger describes in "Being and Time" is rather the case: we can understand life that is not conscious of itself only in analogy with conscious life, and thus as something that somehow, remotely, resembles our own life. We know less what a bat is than what a human being is. Spirit, consciousness, are not opposed to life, as a certain Philosophy of life held, but are rather the highest expression of life. Life in its plenary session of the Executive Council sense is conscious life.

As St. Thomas writes: "He who does not understand does not live perfectly, but has a half-life". Thus it is understood that the Gospel of St. John affirms: light is the life of man; and only God is light, only He is life completely transparent to itself.

Here we could evoke the idea of St. Irenaeus († 202):"gloria Dei vivens homo", the living man is the expression of the glory of God. Man lives more perfectly the more he participates in the love and knowledge that God himself has, so that in the nobility of that life, God is more known and loved. The greatness of authentic human life leads to extolling and praising its Creator: this is called "the glory of God".

According to the encyclical Lumen fidei (29-VI-2013), Pope Francis' first encyclical, it is biblical faith that assures the dignity of the human person, insofar as he or she is created in an unrepeatable way by God and redeemed by Jesus Christ. "When this reality is obscured, the criterion for distinguishing what makes man's life precious and unique is lacking. Man either loses his place in the universe, loses himself in nature, renounces his moral responsibility, or pretends to be the absolute arbiter, arrogating to himself an unlimited power of manipulation" (n. 54).

 When faith is extinguished," Pope Francis continues, "there is a risk that the foundations of life will weaken with it" (n. 55). The poet T. S. Eliot, a witness to the Christian roots of our society, warned: "Do you need to be told that even those modest achievements / Which make you proud of polite society / Will hardly survive the faith that gives them meaning?"(Choruses from"The Rock").

The value of human life, accessible to reason, is confirmed, at final, by the Christian faith. It assures us that divine life is source of all life, and particularly of human life, endowed with intelligence and will, in the image of its Creator. And this is the ultimate foundation of dignity staff, which, according to experience, is assured only when God is present in society and is not expelled from it.