As the prologue to Revelation, Rv 1:1-8 is a highly condensed summary of all the chapters of Revelation. Before we discuss Rv 1:7, we should remind ourselves that Rv 1:7 is also part of that summary.
The fact that Jesus returns with the clouds means that he is coming in spirit. Clouds are capable of hiding things from view. In Acts 1:9-11, Jesus’ disciples were staring into the sky after Jesus’ ascension, and a cloud hid Jesus from their sight.