If you’d recited the Creed before the Second Vatican Council in the mid-1960s, the line you indicate would have read: “Of one substance with the Father.” After Vatican II and before 2011, that phrase was: “One in being with the Father.” The Greek word translated all three ways is homoousion, “single essence.” The Latin word is consubstantialis, bringing us to the current translation, consubstantial—a word you probably won’t hear in any context other than reciting the Creed.

Jesus puts it more elegantly when he declares in John’s gospel: “The Father and I are one.” He makes a similar proposal to Philip, when the disciple innocently asks to see the Father: “Whoever has seen me has seen the Father.”

The first Christian leader to use the term consubstantial was Origin (185-254). He insisted: “There is no dissimilarity whatever between the Son and the Father.” He further declared “the power of the Trinity is one and the same” by quoting Saint Paul: "There are diversities of gifts, but the same Spirit; there are diversities of administrations, but the same Lord; and there are diversities of operations, but it is the same God who worketh all in all.”

The Council of Nicaea (325), dominated by Athanasius, eliminated any hint of subordination within the Trinity. Meanwhile Arius and his followers, who questioned the equal natures of Father, Son, and Spirit, were branded heretical.

Expressions of the single essence of God became the matter of many early homilies. Irenaeus (130-202) trusted that “When Christ comes, God will be seen by men.” Peter Chrysologus (400-450) affirmed that God becomes known to us in being born for us. Bernard of Clairvaux (1090-1153) preached: “In the fullness of time, the fullness of divinity appeared” in Bethlehem.

Some church fathers took consubstantiality a radical step further. Hilary (315-368) proposed: “We are all one, because the Father is in Christ, and Christ is in us…. With Christ we form a unity which is in God.” Cyril of Jerusalem (315-386) went so far as to say: “If we have given up our worldly way of life… it must surely be obvious to everyone that … our nature is transformed, so that we are no longer merely men, but also sons of God, spiritual men, by reason of the share we have received in the divine nature.” Augustine (354-430) dared to speak the phrase that still stuns us: “God became man so that man might become God.” Complete communion with God remains the goal.

Scriptures: John 1:1-5, 14; 5:19-30; 14:7-11; 17:20-26; Romans 13:14; 1 Corinthians 12:4-6; Galatians 2:19-20

Books: The Trinity: Insights from the Mystics, by Anne Hunt (2010)

The Trinity: An Introduction on Catholic Doctrine of the Triune God, by Gilles Emery, O.P. (2011)

We humans have an expression for the pace that makes us impatient: “glacially slow.” Not too slow, we imagine, if you’re a glacier. The biological world moves at a pace quite natural to it, with the rhythm of seasons, centuries, and eons performing an ecological waltz that’s both graceful and, yes, glacial. But human history is running a marathon against time, our little lifetimes being the scale by which we measure what’s an acceptable momentum for change.

This intensified pace of social evolution leads to a phenomenon the pope calls “rapidification.” In Chapter 1 of his encyclical Laudato si, he expresses concern that “the myth of progress” accepts that our present technological juggernaut is sustainable, and that any collateral “ecological problems will solve themselves.” This confidence is irrational, the pope notes. Natural ecosystems are circular: taking, using, and returning goods for the next cycle of life. Human production, by contrast, is linear: taking resources, passing them through non-biodegradable, toxic, and radioactive processes, and returning hundreds of millions of tons of often poisonous waste to the earth.

Our rapidified consumption of resources is having immediate critical effects. The planet is warming. Glaciers are melting at a not-so-glacial pace. Sea level is rising, biodiversity is shrinking, and tropical forests are being lost. Overfishing threatens the oceans’ abundance. Essential resources such as water and agricultural production are waning in availability. Within a few decades, water scarcity is likely to affect billions of people. Animals and plants alike are migrating in an attempt to adapt. This dramatic shift affects human lives, as the poor too must migrate to survive.

The global migrations we’ve already seen, from south to north, are posing complex problems for countries that cannot or will not receive those in motion. Environmental degradation will only worsen these social pressures, setting the scene for more violence and new wars. As the pope says: “The human environment and the natural environment deteriorate together.”

Rapidification is a lifestyle that must be reconsidered. This is not to denounce progress. Unsustainable production, consumption, and disposal is NOT progress, the pope insists. A fundamental shift in our thinking is needed: to strengthen the conviction that we are one single human family. We need to think and act together. The planet is too small, and life is too fragile, to take sides.

Scripture: Genesis 1:26-31; Leviticus 19:9-10; 25:1-7; Deuteronomy 8:7-20; Ecclesiastes 3:1-8; Joel 1:16-20; Matthew 6:25-34; Revelation 22:1-5

Books: Care for Creation: A Call for Ecological Conversion, by Pope Francis (2016)

Apocalyptic Ecology: The Book of Revelation, the Earth, and the Future, by Mical Kiel (2017)