And they came to Capernaum and as soon as the sabbath came Jesus immediately went into the synagogue and taught, and the people were ASTONISHED at his teaching! You won't believe what happened then! Immediately there came a man with an unclean spirit, and Jesus completely shut the spirit down just like that and drove it out, and the people were AMAZED! And they were saying, 'What is THIS!! A new teaching with authority!! He commands even the unclean spirits and they OBEY him!!' And immediately the report of him went out to everybody throughout the WHOLE region!
Ok, so the Word has hit in full force right smack down in rural Galilee, and EVERYONE is blown away like WHOA!!!
This passage is Mark's introductory presentation to Jesus' ministry, and so we can probably see the two elements Mark finds the most important to show right off the bat:
1. The strong reaction of people to both Jesus' teaching and miracles.
2. The power in his teaching and deeds comes from his special "authority".
The reaction of the people in the story is evidently very important to Mark, because this is an important aspect of the hugely central element of Mark's Jesus story, i.e. the continuing flow of people towards Jesus. There is a great attraction to Jesus, and this is painted vividly by the descriptions of people's emotional responses as they are confronted with his words and deeds.
I thought it could be fruitful to take a closer look at this, or at least interesting, so here's an exhaustive list of all the direct descriptions by Mark of emotional reactions to the amazing things that happen throughout Jesus' ministry. There are 26 occurences in 24 verses of 14 different terms throughout the whole narrative. I've also included the centurion, because I felt that incident belonged, although Mark doesn't describe his emotional response.
1:22 εκπλησσω - synagogue-goers are "astounded" in the face of Jesus' teaching
1:27 θαμβεω - synagague-goers are "amazed" in the face of Jesus' authority in teaching and miracle (exorcism)
2:12 εξιστημι - all those at the house are "out of it" in the face of Jesus' miracle (healing the paralytic)
4:41 φοβεω - the disciples "fear" in the face of Jesus' miracle (stilling the storm)
5:16 φοβεω - the Gentiles of the Gerasenes "fear" in the face of Jesus' miracle (healing exorcism of Legion)
5:20 θαυμαζω - the peoples of the Decapolis are "amazed" in the face of the reports of this miracle
5:42 εξιστημι εκστασει μεγαλη - the resurrected girl's family are "out of it in great astonishment" in the face of Jesus' miracle
6:2 εκπλησσω - the synagogue-goers in Nazareth are "amazed" in the face of Jesus' teachings and the reports of his miracles
6:4 εκσκανδαλιζω - they are "offended" by it, because they connect Jesus to his natural family
6:49-51 ταρασσω, εξιστημι - the disciples are "shaken" and "out of it" in the face of Jesus' miracle (walking on water)
7:37 εκπλησσω υπερπερισσως - some Gentiles in Decapolis are "exeedingly astounded" in the face of Jesus' miracle (healing of a deaf-mute)
9:5-6 εκφοβοι - Peter, John and James are "frightened" in the face of a miracle (Jesus' transfiguration)
10:22 στυγναζω - the rich man is "saddened" in the face of Jesus' teaching (one has to sell one's possessions)
10:24 θαμβεω - the disciples are "amazed" in the face of Jesus' teaching (it is difficult for those with wealth to enter God's kingdom)
10:26 εκπλησσω περισσως - the disciples are again "exeedingly astounded" in the face of Jesus' teaching (easier for a camel)
10:32 θαμβεω, φοβεω - those walking with Jesus as he progresses towards Jerusalem "are amazed" and "fear"
11:18 εκπλησσω - Jesus' opponents fear Jesus, because the crowd is generally "astounded" in the face of his teachings
12:17 εκθαυμαζω - some pharisees are "utterly amazed" in the face of Jesus' teaching (render to caesar)
12:37 ηδεως - a large crowd hears "with pleasure" to Jesus' teachings
15:5 θαυμαζω - Pilate is "amazed" when Jesus doesn't defend himself against the accusation of royal-pretender
15:39 the centurion reacts with his "son of God" exclamation in the face of the manner of Jesus' death
15:44 θαμβεω - Pilate is "astonished" at the report that Jesus has already died
16:5 εκθαμβεω - the women at the tomb are "utterly astonished" at the sight of the angel
16:8 τρομος, εκστασις, φοβεω - the women have "trembling and astonishment" and they "fear"
1:27 θαμβεω - synagague-goers are "amazed" in the face of Jesus' authority in teaching and miracle (exorcism)
2:12 εξιστημι - all those at the house are "out of it" in the face of Jesus' miracle (healing the paralytic)
4:41 φοβεω - the disciples "fear" in the face of Jesus' miracle (stilling the storm)
5:16 φοβεω - the Gentiles of the Gerasenes "fear" in the face of Jesus' miracle (healing exorcism of Legion)
5:20 θαυμαζω - the peoples of the Decapolis are "amazed" in the face of the reports of this miracle
5:42 εξιστημι εκστασει μεγαλη - the resurrected girl's family are "out of it in great astonishment" in the face of Jesus' miracle
6:2 εκπλησσω - the synagogue-goers in Nazareth are "amazed" in the face of Jesus' teachings and the reports of his miracles
6:4 εκσκανδαλιζω - they are "offended" by it, because they connect Jesus to his natural family
6:49-51 ταρασσω, εξιστημι - the disciples are "shaken" and "out of it" in the face of Jesus' miracle (walking on water)
7:37 εκπλησσω υπερπερισσως - some Gentiles in Decapolis are "exeedingly astounded" in the face of Jesus' miracle (healing of a deaf-mute)
9:5-6 εκφοβοι - Peter, John and James are "frightened" in the face of a miracle (Jesus' transfiguration)
10:22 στυγναζω - the rich man is "saddened" in the face of Jesus' teaching (one has to sell one's possessions)
10:24 θαμβεω - the disciples are "amazed" in the face of Jesus' teaching (it is difficult for those with wealth to enter God's kingdom)
10:26 εκπλησσω περισσως - the disciples are again "exeedingly astounded" in the face of Jesus' teaching (easier for a camel)
10:32 θαμβεω, φοβεω - those walking with Jesus as he progresses towards Jerusalem "are amazed" and "fear"
11:18 εκπλησσω - Jesus' opponents fear Jesus, because the crowd is generally "astounded" in the face of his teachings
12:17 εκθαυμαζω - some pharisees are "utterly amazed" in the face of Jesus' teaching (render to caesar)
12:37 ηδεως - a large crowd hears "with pleasure" to Jesus' teachings
15:5 θαυμαζω - Pilate is "amazed" when Jesus doesn't defend himself against the accusation of royal-pretender
15:39 the centurion reacts with his "son of God" exclamation in the face of the manner of Jesus' death
15:44 θαμβεω - Pilate is "astonished" at the report that Jesus has already died
16:5 εκθαμβεω - the women at the tomb are "utterly astonished" at the sight of the angel
16:8 τρομος, εκστασις, φοβεω - the women have "trembling and astonishment" and they "fear"
Generally there are two categories, amazement and fear, but as human emotions go these are of course often intertwined. Further, it is sometimes hard to tell whether the amazement is positive ('whoa, awesome!') or negative ('holy shit!') or simply just plain bewilderment ('how strange!')
These are of course only the places where Mark narrates the emotional responses directly, and the list of responses generally would be much longer. But it's clear even from this that it is of immense concern to Mark to elaborate on the reactions of people as they are confronted with the Word in action, as it were. It also makes for vivid storytelling. And the more Mark spells out the emotional responses the more we get the sense of the power which manifests itself through Jesus' words and deeds. The descriptions themselves of these responses awakens in the readers a natural interest in Jesus and his teachings and deeds. Tell us more about Jesus' amazing feats!
The fact that we humans enjoy the strong reactions of fellow humans has also come to the attention of media and advertizers. I mean, consider click-bait headlines. And there's even the whole genre on youtube of 'reaction-videos' where people earn thousands by simply pointing a camera at their own faces and recording their reactions to various things such as music videos or whatever. It's not the thing itself which attracts all those hundreds of thousands of viewers, it's the other person's reaction to the thing which people come to see. How odd is that.
And if you want a viral video, a good advice is a video which contains the element of people's strong reactions to something, but it needs to be understood as real emotions. Doesn't really matter what it is, as long as there are people who react strongly to it, that's what sells. Case in point, Momondo's masterful DNA commercial. Watch as these people are utterly amazed, astonished and astounded! https://www.youtube.com/watch?v=tyaEQEmt5ls
(spoiler: it's produced with actors mixed in with real participants!)