I'm going to try to keep this shorter than my other entries, so I'm just going to point out an assortment of things I like rather than doing a full breakdown.
One of the things that I like about this song is how it can produce a somewhat ethereal feel without having any rhythmic intensity. The group does this by emphasizing a wide range of electric keyboard sounds and using a light bass feel. The opening rhythmic figure of sixteenth note dotted eighth note by the keyboard gives the first few measures rhythmic drive into the entrance of the drums. And as with many rock songs, there is usually a break between each line of the verse and use of a quick run with a harp sound. The importance of this of course is that the song is about miracles (like Ohio State beating Illinois!, okay, maybe not, the game just ended) of the past and miracles of the future.
Another nice addition to the song is the chords that are at the end of the chorus. I call them the "Bee-Gees" chords because they could come straight from one of those songs and all the background stops except for the echoing of the bass, and some hi-hat near the end to set the tempo for the next section.
And like any good Queen song, there are guitar solos. There are four of them in this song (two stand alone sections, and two as transitions) and they use single line in the upper range of the instrument with a clear tone that fits in with the theme of the song.
After a couple rounds of the verses and chorus and the lyrics subject changing from past miracles to future miracles "peace on earth an end to war" the song changes mood by having a driving bass doing dotted eighth, eighth, three sixteenths twice per 4/4 bar and there is another guitar solo, but this one much in a more regular range for guitar and also has some distortion in it. The rhythms are also much more jagged. The drums also take some liberty in doing some very highly syncopated solos. This section seems very out of place in this song, but the meaning is realized when the vocal comes in at a completely different slower tempo with the lyric, "that time will come, one day you'll see, when we can all be friends" after this line is completed, all of the craziness of the instruments comes into sync with the vocal line, which gives a great effect. This lyric and the instrumentation that is reminicient of the early part of the song fades out as the song completes. I see the crazy section as the world today, and the final lyric part as being the hope of tomorrow.
This song does a good job of combining instrumentation to create a song full of different emotions.