The passage
      v21. In v29 we see that the "they" are the four fishermen who have "left their nets and followed" Jesus. Most likely they all lived in Capernaum, a town situated on the northwestern shore of lake Galilee. The ruins at Tel Hum today probably represent this thriving town that Jesus made the center for his ministry. In typical fashion, Jesus, a wandering rabbi (teacher), attends the local synagogue and is invited to expound the scriptures to the congregation. At the outset, Mark identifies the substance of Jesus' mission; Jesus is into divine communication.
      v22. The content of his teaching was most likely the gospel, a summary of which is found in v15. Obviously, the content, along with the authority with which it was delivered, disturbed the people. Jesus delivered his teaching quite contrary to the rabbinic tradition where the scriptures were expounded in line with the tradition of the elders. Jesus launched out in a style even more confronting than the prophets of old. Here was an authoritative revelation from God which served to amaze the congregation.
      v23. A man, possessed by an evil spirit, then enters the synagogue. His personality is so damaged that the powers of darkness now rule his will. Faced with the danger of God's son, the demon screams in terror and rage.
      v24. The demon proclaims the name of Jesus, his function and his title, "Holy One of God". He (it/they) does this to gain mastery over him. In the name there is power. If he can precisely identify him, he may be able to contain his power (or so was the belief of the day). The demon denounces Jesus' right to interfere with him, "what have we to do with you? (you have no business with us). He declares that he and his demonic friends know what Jesus is on about (judgement) and who he is (God's messiah) and therefore, Jesus should mind his own business.
      v25. The evil spirit's ploy is useless before God's messiah. Without resting on some invocation to the divine (symbols, spells, techniques), Jesus tells him to "shut up" and "come out". When it comes to the powers of darkness, Jesus has absolute authority over them.
      v26. Jesus came to confront the powers of darkness and strip them of their power. In the face of the authoritative judge, the powers shriek in defiance, but come out, silenced and broken.
      v27. The congregation is totally astonished. They have never before witnessed such an authoritative teaching. Here is a rabbi who declares a word without reservation (not even "thus says the Lord", but "I say unto you"). When this authoritative word is directed toward demonic powers, they scatter in fear. "Here was a teaching qualitatively new in the authority with which it laid hold of men. And the people were alarmed", W. Lane.
      v28. News of the disturbance spreads far and wide.

The power of God's Word
      In this story, in fact in all Jesus' exorcisms, we see the activity of God gaining control over a creation separated from him and now hostile to him, a creation subject to dark forces. These hostile powers are brought under God's rule by an authoritative word from the divine man, Jesus.
      In grammar, the Mood denotes the way we should understand the action of a verb. For example, a verb in the Subjective Mood denotes a thought or wish, rather than an actual fact. The Indicative Mood makes a general statement, expresses a truth or factual observation (eg. We sing). The Imperative Mood gives a command. The Bible is full of commands. We are commanded to work out our salvation with fear and trembling. We are commanded to strive toward the perfection we possess in Christ. Such commands often leave us with the impression that our right-standing before God (justification), and our progress in Christ-likeness (sanctification), is a matter of effort. That getting saved and staying saved, is a good work.
      Believers tend to divide into two groups when confronted with the issue of salvation. Some are Calvinist (God chooses us) and others are Arminian (we choose God). Is it both? One of the hot issues of debate is whether it is possible to lose our salvation. A Calvinist will argue "once saved always saved." Yet, scripture does warn us that we can lose our salvation, at least in theory. We can choose to walk with Christ or choose not to walk with him. The interesting fact is that Arminius, unlike his followers, was not convinced that a regenerate believer could lose their faith. Having once tasted Christ, who could cast him away?
      We are kept in the game of faith, kept on the narrow way, by the power of the Biblical Imperative. The authoritative Word of Christ commands, and in the strength of the Spirit of Christ, those hostile powers that would undermine our faith, are subdued. We hear and are set free by the grace of Christ's authoritative Word.

v22
      exeplhssonto (ekplhssw) imperf. "the people were amazed" - they were amazed, astonished, overwhelmed, filled with fear and wonder. The tense links to Jesus' act of teaching in v21, indicating that from the moment he began teaching, the people were astonished. It is worth noting that the gospel ends with the women overcome with trembling, amazement and fear, 16:8. This response to Jesus and his gospel, is well short of faith and it seems clear that Mark wants to underline the need to move from wonder to faith. "The people were astonished at his teaching", NAB.
      epi "because" - upon, at. Here "at", in the sense of "on the ground of" = "because of"
      th/ didach/ (h) dat. "teaching" - Are the people amazed at how he taught, or are they amazed at the content of his teaching - radical ideas or bold presentation? Commentators are divided. How about both?
      hn didaskwn "he taught" - he was teaching. Periphrastic imperfect. Here a true periphrastic construction and therefore, probably best treated as a simple imperfect, ie. it is used only for stylistic flair. It is possible that Mark is using the periphrastic for emphasis, "there he was, teaching them", France.
      exousian (a) "authority" - authority, power, ability. These three possible meanings indicate the difficultly in identifying what it was about Jesus' teaching/presentation that prompted amazement. Was it his use of "I say unto you", rather than "thus says the Lord", an aura of the divine about him, or his knowledge and debating skills? The first option seems best. "He taught like a teacher who needed no authority other than his own", Barclay.
      oiJ grammateiV (uV ewV) "the teachers of the law" - scribes. Recognized theological authorities.

v23
      euquV "just then" - immediately. Maintaining dramatic movement. In response to Jesus' teaching, not on his entering the synagogue.
      en "in [the synagogue] - in. Probably here meaning, "came", "appeared". "While Jesus was teaching, a person, possessed by an evil spirit, entered the synagogue and began screaming."
      anqrwpoV (oV) "a man" - man. Anarthrous noun, so "someone."
      en pneumati akaqartw/ "who was possessed by an evil spirit" - with an unclean / defiled / evil spirit. "With" = "having" = "under the influence of", BAGD.
      anekraxen (anakrazw) aor. "cried out" - he/it cried out. Who cried out, the man or the unclean spirit? In demon possession, the personality of the demon is distinct from, and in control of, the host. So, it is probably the demon who is enraged at the presence of Jesus, rather than the man crying out for help.

v24
      ti hJmin kai soi "what do you want with us?" - what to us and to you. This idiomatic saying has a number of possible meanings: "What have we and you in common", Classical Greek; "why do you interfere with us", cf. Taylor; "mind your own business", Cranfield; "go away and leave us alone", France. Note the plural "us"; meaning spirit and host, or numerous possessing spirits, or one spirit speaking for all his friends?
      hlqeV (ercomai) aor. "have you come - Possibly a question, but the clause may also be a statement; "you have come into the world ....."
      apolesai (apolumi) aor. inf. "to destroy" - The infinitive is expressing purpose; "in order to destroy."
      oida, oidamen "I know" - I / we know. Variant "we".
      se tiV ei "who you are" - [I know] you who are you. The interrogative "who are you" is what they know. It was believed that by knowing a person, power was gained over them. The demons knew Jesus: his name, Jesus of Nazareth; his business, judgment; and his spiritual nature, messiah. "We know who you are and so you have no power over us."
      oJ aJgioV tou qeou "the Holy One of God" - the holy of God. The genitive "of God" may mean "from God", or "who belongs to God." "The "holy of God", may mean "the holy man of God", but Mark probably intends the phrase as a messianic title.

v25
      fimwqhti (fimow) aor. pas. imp. "be quiet" - be muzzled. "Silence!", Barclay; "hold your tongue", Phillips.
      kai epetimhsen autw/ oJ IaswouV legwn "said Jesus sternly" - and Jesus rebuked, censured, warned, spoke sternly to him saying. Probably here the sense is of an authoritative silencing: "Jesus commanded him/it to stop speaking / told him to shut up." Jesus is possibly just cutting short the unclean spirit's self defense, but he may also be wanting to maintain the messianic secret which requires a subtle revelation of the Christ ("Son of Man") for those with eyes to see, rather than an overt display of a popular messiah with inevitable political complications.
      exelqe (exercomai) aor. imp. "come out" - Jesus teaches with authority and this authority is demonstrated in his command over demons.

v26
      sparaxan (sparassw) aor. part. "shook [the man] violently" - having convulsed, torn apart, pushed and pulled toe and fro. The participle possibly forms a temporal clause: "after throwing the man into convulsions", Weymouth.
      fwnh/ (fwnew) aor. part. "with a shriek" - having cried out, shouted out. The aorist tense of both participles, "having convulsed and having shouted out", links them together in time. The shaking and shouting probably illustrates resistance, although ineffectual. "The evil spirit convulsed the man, let out a loud scream and left him", Phillips.

v27
      eqambhqhsan (qambew) aor. pas. "were all so amazed" - was astonished, amazed, astounded. Taylor suggests that they were astonished because Jesus cast out the demon without the usual incantations and actions, ie. it's a style issue. Jesus does it with a word of command. It is also quite possible that exorcisms were not commonplace. "They were dumbfounded", Williams.
      wJste + inf. "that" - so that, so as. Expressing result, "so as to."
      suzhtein (suzhtew) pres. inf. "they asked [each other]" - to discuss, question, dispute with. "They discussed it with one another", Goodspeed.
      didach kainh "a new teaching" - "'New' in respect of quality, as distinct from 'new' as regards time", Taylor.
      kat exousian "with authority" - "It's new teaching with authority behind it", Moffatt.
      kai "even" - and. Adverbial use, "even", emphasizing the authoritative word exercised over the demons is more amazing than Jesus' authoritative word in teaching, which in itself is amazing. "Why, he even gives orders .....", Phillips.