Three Greek verb families dominate the way Paul, Peter, John, and the writer of Hebrews address churches. Each carries a quite different weight of authority, and the choice between them is doctrinally significant.
parakaléō (παρακαλέω) — appeal, urge, exhort, beseech, implore
The dominant verb across the New Testament epistles. This is brother-to-brother persuasion language — the verb you reach for when you have a stake in the outcome but you are asking, not ordering. It carries warmth, urgency, and personal investment, but explicitly not institutional command.
paraggéllō (παραγγέλλω) — charge, instruct, hand down a directive
Stronger than appeal. The verb of formal instruction — used for ethical instructions, often where the Lord Himself has spoken. When Paul uses this word he is usually transmitting Christ's commands, not issuing his own.
epitássō (ἐπιτάσσω) — command with authority
To order, to direct authoritatively. This is the verb of institutional command. Rare in Paul's letters — and in the most important case, he explicitly refuses to use it when he could.