English lessons you can learn from this song are:
1. Use of the conditional 'if', type 1. Example: If you MISS the train I'm on, you WILL KNOW that I am gone.
The point to notice here is--the Present Simple tense is used with the 'If' part of the sentence, but the Future Simple tense is used with the other part of the sentence.
You can study and practice more on this in unit 111 of the red grammar book. My version for an easy sentence to remember would be: If he COMES, I WILL GO.
You can study the conditional 'if', type 2, my version: If he CAME, I WOULD GO, in unit 112 of the red book and unit 39 of the blue book, new edition (old edition=38).
You can also study type 3, my version: If he HAD COME, I WOULD HAVE GONE, in unit 40 of the blue book, new edition ( old edition=39).
2. Note that in the phrase 'a hundred miles', though there is 'a', the word 'miles' is plural with an 's' because 'a hundred miles'='100 miles'.
3. The expression 'the tide will turn' = 'things will change in the opposite direction'.
4. Lord = God.
Hope you enjoy the song and can learn something from it.