The Greek adverb adialeiptōs (ἀδιαλείπτως) means without ceasing, unceasingly, incessantly, or constantly. It derives from a- (not) + dialeipō (to leave off, cease, interrupt), thus "without interruption." It appears four times in the New Testament: Romans 1:9; 1 Thessalonians 1:3; 1 Thessalonians 2:13; and the famous 1 Thessalonians 5:17 — "Pray without ceasing (adialeiptōs)." Paul uses the same word to describe his own unceasing prayer for his congregations.
1 Thessalonians 5:17 — "Pray without ceasing" (adialeiptōs) — is one of the most challenging and life-transforming commands in all of Scripture. How does one pray without stopping? The early church fathers interpreted adialeiptōs not as literal verbal prayer every moment, but as a posture of the heart — a constant orientation toward God in which all of life becomes a form of prayer. Brother Lawrence called it "practicing the presence of God." The Desert Fathers developed the Jesus Prayer ("Lord Jesus Christ, Son of God, have mercy on me, a sinner") precisely to fulfill this command — a short prayer repeated until it becomes as natural as breathing. Paul himself models adialeiptōs: Romans 1:9 — "God, whom I serve… is my witness how constantly (adialeiptōs) I remember you in my prayers at all times." Ceaseless prayer is the oxygen of the spiritual life — the soul that stops breathing prayer begins to suffocate.