The first three verses of the book of Revelation are an introduction to the book as a whole. The following 5 verses, verses 5 through 8, are the letterhead. We then read in verses 9 through 11 how John is instructed to write down what He hears and sees.
Emphatically, John says that he is now speaking again. In verse 8, we heard God speak; now John begins to speak. He says three things of himself. First, he is a brother and fellow member in tribulation and suffering. “I John, who also am your brother, and companion in tribulation.” John positions himself alongside his sheep. He too, knows tribulation just as they do. This also shows that tribulation is not something that comes with it, tribulation is always there, although the degree, intensity, and nature will vary. Second, he says that he is a fellow brother in the kingdom. “And in the kingdom.” Like them, he is a citizen of two worlds. Here on earth, he is a stranger and sojourner, along with all who belong to Christ’s body. Where they truly belong is with Christ, in heaven. Third, he notes that he is also a brother and sharer in the long-suffering of Christ. “And patience of Jesus Christ.” The word used for patience can also translate as endurance or perseverance. As Christ endured, so His child endures. Perseverance is necessary in the trials that come our way. But to have that indispensable perseverance, God’s child needs to be in Christ and in His Word (John 15).
John receives his visions on the Lord's Day, the Resurrection Day, Sunday. That is remarkable and significant for us. Let us gather on the first day of the week to listen to God’s Word and worship the Lord with our fellow brothers. John is on the island of Patmos, to which he is exiled. This exile makes evident that he personally knows what tribulation and bearing the cross after Christ is. And there and on that day of the Lord, John is "in the Spirit.” The Holy Spirit controls him, takes him, and shows him visions.
The first vision begins with a great voice, "as of a trumpet.” God is taking the word. In the Old Testament, the trumpet is the instrument that calls to gather, but it is also the instrument that calls to battle and thus then has a warning function. So, it is also here, God's voice is like a warning. God calls to hear His word, to really pay attention to them.
Then God instructs John to write down what he hears and sees and send it to the seven churches. And so we also receive these words.