Doors and doorways are places of transition. We pass through them to get from one place to another. An open door allows access, while closing a door will block access to those who are outside, allowing us privacy and peace (Matt. 6:6).
The Bible uses the imagery of an open door to refer to an opportunity for the gospel. On one occasion, Paul expressed his desire to spend time with the Christians at Corinth, but found it necessary to remain in Ephesus longer. "But I will tarry in Ephesus until Pentecost. For a great and effective door has opened to me, and there are many adversaries" (1 Cor. 16:8-9). Paul found a unique opportunity to preach the gospel in Ephesus, and he was going to stay and take advantage of it. On another occasion, Paul instructed the Colossians to pray "that God would open to us a door for the word, to speak the mystery of Christ, for which I am also in chains" (Col. 4:3). The Lord had given the church in Philadelphia "an open door, and no one can shut it; for you have a little strength, have kept My word, and have not denied My name" (Rev. 3:8). They had been found faithful, therefore they would have increased opportunities to spread the gospel.
Not only does God open doors of opportunity for us, He sometimes closes doors. Paul experienced this when he and his companions were traveling westward through Asia Minor.
"Now when they had gone through Phrygia and the region of Galatia, they were forbidden by the Holy Spirit to preach the word in Asia. After they had come to Mysia, they tried to go into Bithynia, but the Spirit did not permit them. So passing by Mysia, they came down to Troas" (Acts 16:6-8).
Paul and his companions tried to turn aside to take the gospel into different areas, but they were forbidden to do so by the Holy Spirit. Instead, they made a straight line to Troas, where Paul received the "Macedonian Call" (vs. 9-10). Paul wanted to go to Asia and Bithynia, but God wanted him to go to Macedonia. It can be very disappointing when things do not work out as we have planned. We need to remember that sometimes plans don't work out for us because God has something else waiting for us behind a different door.
There is another door spoken of in Scripture: a door which God does not open for us, but which we open for God. This is the door of our heart. "Behold, I stand at the door and knock. If anyone hears My voice and opens the door, I will come in to him and dine with him, and he with Me" (Rev. 3:20). God has granted man free will, which means He gives us the power to open our hearts to Him. God wants to have fellowship with us, but He will not force Himself upon us. We have to choose to open our heart and invite Him into our lives.
There is a danger in ignoring God's call for fellowship. If we choose not to open our hearts to God, we will one day discover that He has closed the door of the kingdom to us. "Strive to enter through the narrow gate, for many, I say to you, will seek to enter and will not be able. When once the Master of the house has risen up and shut the door, and you begin to stand outside and knock at the door, saying, 'Lord, Lord, open for us,' and He will answer and say to you, 'I do not know you, where you are from'" (Luke 13:24-25).
Look around you. Has God opened doors of opportunity for you to talk with people about their need to obey the gospel? Are you praying for such opportunities? Does a particular door appear to be "shut" at this moment? Such can be disappointing, but do not despair. God may want you to enjoy another blessing or take a different challenge at this time. Are you without God in your life? God wants you to be saved from your sins by obeying the gospel. Open the door of your heart to the Lord before it is too late.