"Shut that door!" was the name given to a British comedy talk show hosted by Larry Grayson in the seventies. I don't recall ever having watched the show, but the words also became something of a "catch-phrase" among the general public.
Why would we want to shut a door? Well, there are many reasons. If it is an outside door, it may well be to stop a draught. We think of a closed door as a means of keeping out those who are unwelcome. I recall being on holiday, many years ago, in a certain seaside town in Scotland. We must have only arrived on a Saturday evening but, for whatever reason, we did not know the time at which the worship service commenced for the local church with which we had decided to meet on the Sunday morning. We arrived at the building in what we thought would be plenty of time. However, we then discovered that the service commenced fifteen minutes earlier than we had anticipated - and that, already, the doors were shut! We were less than impressed!
However, a shut door may also signify that we desire to be shut in with someone who is very dear to us, and with whom we wish to spend time without any interruption. This, of course, is the sense in which the Lord Jesus spoke of the need for seclusion if His disciple wants deep, and sweet, communion with God in prayer.
In what we know as "the Sermon on the Mount", Jesus told the people that, when they pray, they should go into their room and shut the door! The word translated "room" means "a place of retirement and privacy." In the privacy of their own room - or, if one does not have a room of one's own, in any private and secluded place - the Heavenly Father will meet with His child in holy intimacy. By the very act of deliberately closing themselves off from everything outside, one is better able to be in a position of openness to God.
Of course, as I reminded the congregation on Sunday, the devil doesn't like it when we pray; and I know from personal experience how easily distracting thoughts fill my mind as I seek to do so. These are, usually, perfectly acceptable thoughts - but they are still a distraction!
This practice of drawing aside is illustrated, to some extent, by the event recorded in John 20:19. Following the resurrection of Jesus, the disciples met, in seclusion, because they feared that their enemies. John records: "On the evening of that day, the first day of the week, the doors being shut where the disciples were, for fear of the Jews, Jesus came and stood among them and said to them, “Peace be with you.”" (emphasis added). We might say that, when we shut ourselves off from the world, behind our shut door, in prayer, that it is an invitation to the risen Lord to fellowship with us! In the solitude of what we used to call the "Quiet Time", He may meet with His disciple in a special way, and bring strength to a needy heart.
By separating yourself from the din and distraction of people and things you will demonstrate how important is communion with Him; and you will be better able to both open yourself to Him, and hear His response in your heart. That, I would claim, is when you will find power to live for Him.