After Jesus ascended into Heaven, His followers were met by an angel who said, “This Jesus, who was taken up from you into heaven, will come in the same way as you saw him go into heaven.” This phrase laid out an important expectation that has characterized the rest of history.
Over the centuries, Christians have disagreed (even strongly, at times) about exactly how the return of Christ will take place: Premillennialism, Postmillennialism, Amillennialism, Dispensationalism, Idealism, Partial Preterism. But the universal constant has been the belief that Jesus will return. This belief is what helps to unify us in our expectation and our mission.
If we know that Jesus will return, we know that there are things we should be accomplishing, goals we should be meeting, and preparations we should be making. That will be the focus of our service today. If Christ is coming again, then we are aware of the greatest event in history and have no excuse to be unprepared.