Voice

5.3. Voice
Greek verbs also have three voices: active, passive and middle.
5.3.1. Active
In the active voice, the subject performs the action. Εσωσεν (esōsen) G4982 V-AAI-3Sημας (ēmas) G2248 P-1AP ‘He saved us’ (Titus 3:5). The subject here is God. He saved us. This truth is illustrated beautifully somewhere else, when the multitude in Revelation 7:10 shouted in a loud voice: ‘Salvation belongs to our God, to the one seated on the throne, and to the Lamb!’
5.3.2. Passive
In the passive voice, the subject is acted upon or receives the action. Χριστος (Christos) G5547 N-NSM κηρυσσεται (kērussetai) G2784 V-PPI-3S ‘Christ is preached’ (1Cor. 15:12). Christ is not preached by himself, but by others, his messengers.
5.3.3. Middle
In the middle voice, the subject produces and receives the action. However, one has to be careful. Do not rely on your own judgement. Consult the scholars. Απεχεσθαι (apexesthai) G567 V-PMN ‘Keep yourself away from’ (1 Thess. 4:3).