Jesus was born to a woman on the earth, was crucified, went to heaven with God the Father, He is reigning there now, He will return, but we don't know when. The Bible says we should be ready at any given moment because we do not know when He will come. We wouldn't want Him to come back and we are not ready, disobedient. Just like an earthly boss, we want to be found doing good work. So much more for our heavenly Boss.