Tunnels too- if they are dug out, they become opened and once they are organized and opened, lines of cars travel through them daily. In this way, when it comes to communication, you must continually communicate like a tunnel being constantly dug out. Then it becomes opened.
Even if the opening happened, if communication does not happen, it will become blocked again. Whatever is blocked must be opened again by continual communication.
Sermons of Pastor Jung Myeong Seok
