Tempus, Aevum, Aeternitas

The scholastic distinction (Aquinas, Summa I.10) names three modes of duration: Tempus — measured, successive time, where bodies live; Aevum — the long-now of created persistence, where angels and souls are; Aeternitas — the atemporal, undivided present, where God is. The categories are interpretive; the witness is scriptural:

"But don’t forget this one thing, beloved, that one day is with the Lord as a thousand years, and a thousand years as one day." — 2 Peter 3:8 "He has made everything beautiful in its time. He has also set eternity in their hearts,." — Ecclesiastes 3:11 "Before the mountains were born, before you had formed the earth and the world, even from everlasting to everlasting, you are God." — Psalm 90:2 "For a thousand years in your sight are just like yesterday when it is past, like a watch in the night." — Psalm 90:4

The eternal is not "very long time"; it is a different mode entirely. The Logos is its address. Moses, naming the asymmetry, asks the only sane response to it: "So teach us to number our days, that we may apply our hearts unto wisdom" (Psalm 90:12). The numbering of days is wisdom precisely because the modes do not match — what is brief in tempus is fully present in aeternitas.

See: Psalm 90 (whole psalm, especially v. 2, 4, 12); Ecclesiastes 3:11; 2 Peter 3:8; Revelation 1:8; 22:13.