"The Coming One" was a title for Messiah. "The Coming One" was a special name for Messiah. In fact, back in Matthew we have an interesting reference to it. I’ll just read it to you. In Matthew, John the Baptist was in prison and he sent word by his disciples to Jesus. And they said to Him, "Are You the Coming One?" You see, the Jews all knew that the Coming One was a Messianic title. Jesus is the Coming One. That same verb, erchomai [???], that means "coming," is used directly or indirectly with reference to Christ nine times in the book of Revelation. Seven of those nine times it is the words of Jesus Himself, referring to Himself as "the Coming One."
This book, then, is about the coming of the Coming One. And the present tense indicates to us that He’s already coming, so that we have this sense of expectation that leads John to say, "Look, He is coming," as if we are to be living in eager expectation. This, again, is the great heart of the book [of Revelation].
For every time the Bible mentions the first coming of Christ, it mentions the second coming 8 times. For each time the atonement is mentioned once, the second coming is mentioned twice. Jesus refers to His second coming 21 times, and over 50 times we are told to be ready for His return.
Over 50 times we are warned to be ready for His return? Wow. Yet for all the lack of preaching and teaching on it, one would think it is not important. But it is highly important. I recommend MacArthur's sermon series in Revelation, linked above. My personal opinion is that his best book has been Because the Time is Near, an overview of Revelation.
Through death, rapture, or Judgment, you will meet Him. Are you ready?
Alistair Begg/Truth for Life Devotional: Be Ready
Ligonier Devotional: Discerning the Signs
Grace to You Article: Marks of a Committed Christian