In verse 7 we find a combination of two texts from the Old Testament. The "coming with the clouds" reminds us of the Son of man in Daniel 7:13. That those who pierced him will mourn over Him, echoes Zechariah 12:10. Matthew 24:30 also combines the same two texts, so Revelation 1:7 may reflect Jesus' earlier teaching.
In Zechariah the ones who pierce and mourn are "the house of David" and the "inhabitants of Jerusalem." But Revelation changes it to "all the tribes of the earth," a common shift in the book. It applies the literal and local things of the Old Testament in a spiritual and worldwide manner. The concept of "Israel" expands to include people of any race and place who are in relationship with Jesus.
So the key to inclusion among the people of God is a connection with His Son. But how can you have a relationship with Jesus when you can't see, hear, or touch Him? That possibly was abundantly illustrated by the most-watched movie of all time, Titanic. Titanic earned twice as much money from theater admissions as any other movie until then. The popularity of the film had a rather trivial reason. Millions of teenage girls in North America became smitten with the handsome young male lead, Leonardo DiCaprio. Many went back to see the movie several times. Some claimed to have seen it more than 40 times! They were developing a relationship with someone they couldn't see, hear, or touch in person! Few of them had ever encountered DiCaprio in real life.
How could this be? The movie was not Leonardo himself. But it was a witness to the reality that was the actor. And millions of teenage girls found that witness sufficient for a serious relationship. Whereas millions will testify to the existence of Leonardo DiCaprio and the influence he may have had in their lives, billions through the centuries have testified to the reality of Jesus, most basing it on the testimonies found in the sacred and inspired pages of Scripture.
It is clear that you can have a living relationship with someone you cannot see, hear, or touch. When it comes to Jesus, you develop that relationship by spending time with the witness about Him in His Word. You need to invest in serious Bible study as well as talk to other people who know Him and hear their testimonies about His impact in their lives. And you need to get involved in the mission that He left for His disciples (Matt. 28:20) to accomplish. Those in relationship with Jesus will one day participate in the glorious victory portrayed in Revelation.
Lord, I need the presence of Jesus to be real in my life today. May His Word become flesh in everything I do or say.