At different times in the Bible different people were permitted to peer through an open door, as though they looked into heaven (Ezekiel 1:1; Matthew 3:16; Acts 7:56; 10:11). Different visions were seen, but each one was very significant in its own context. John’s open door, in my opinion, must be viewed in the context of Revelation 1:19. That is, John saw certain things in chapter one, and in chapters two and three, he explained what those things are. In other words, he recorded the meaning in chapters two and three of what he had seen in chapter one. Finally, John was commanded “Come up here, and I will show you what must take place after these things” (Revelation 4:1), which in the context of Revelation 1:19 is to see “the things” beyond the Holy Place, where the seven lamps stood before the throne (cf. Revelation 1:12 and 4:5).
It is interesting to note here that the seven lamps burned before the throne, but in the context of the Temple, the seven lamps burned in the Holy Place, and a veil separated the lamps from the throne, or the Mercy Seat within the Most Holy Place. It seems, therefore, that John’s open door signifies the removed veil that separated the two rooms in the Temple building, the Holy Place from the Most Holy Place. Moreover, as mentioned above, calling John to enter the door in heaven puts heaven in the perspective of entering the Presence of God within the veil or within the Holy of Holies. It is where heaven and earth came together. John entered there and “was immediately in the Spirit.”
A trumpet was used to call the assembly of the people at the door of the Tabernacle, but, if only one trumpet was blown, only the princes of the people would assemble (Numbers 10:1-4). The trumpet was also used for the journeys of the people (Numbers 10:5-6, 9), but this was an alarm, a different sound than for assemblies (Numbers 10:7). The trumpets were blown only by the priests, and they were also used for worship during the times when the people appeared before the Lord (Numbers 10:8, 10). Sometimes, a loud voice, announcing the approach of an enemy or pointing to the sins of the people was considered a trumpet (Isaiah 58:1). In fact, when the Lord came down upon Mount Sinai with the blast of a trumpet, that may have been the sound of his words, not an actual trumpet blast (cf. Exodus 19:16. 10; Hebrews 12:19; Deuteronomy 5:24-27). I believe it is in the context of a loud voice that we should understand Revelation 1:10 and 4:1, and that voice was calling John to come into the Presence of God (cf. Numbers 10:1-4).
The voice told John: “Come up (G305) here, and I will show you what must take place after these things” (emphasis and parenthesis mine). Most often in the Scriptures this Greek word is used to mean ascend or to come or go up, however in the Septuagint it is used figuratively on at least one occasion:
The foreigner who is among you shall ascend (G305) over you upward and upward; but you shall go down lower and lower. (Deuteronomy 28:43; emphasis and parenthesis mine)
My point is that no matter where one was in the Roman Empire, if anyone traveled to Jerusalem, he always ascended or went up to Jerusalem. If one traveled away from Jerusalem, he always descended or went down from Jerusalem to wherever he intended to go. In other words, going up in Revelation 4:1 is as much an expression of respect as it is of direction. So, if one went from the Holy Place to the Most Holy Place, one would ascend or go up into the Presence of God.
The translators of Revelation 4:1 take the things John was to see in heaven and place them into the future, but this is not necessarily so. As I mentioned in a previous study, the Greek word for after (G3326) does, indeed, refer to future events, but it can also refer to someone physically among (G3326) a list of others (cf. Luke 22:37; 24:5; John 6:43; 11:56; 16:19), or after in the sense of being in the next room (cf. Hebrews 9:2-3). So, when John was told he would see things after these things, he was told he would see things being done in the Most Holy Place, just as he saw things done in the Holy Place of the Temple.
Those things done in the Most Holy Place may or may not be in the future with respect to what he had already seen. For example, while in the Holy Place John saw or was told that Antipas was the Lord’s faithful martyr, and he was slain among believers in the church at Pergamum (Revelation 2:13). Yet, in Revelation 6:9-11 and at the opening of the fifth seal, the elect who were presumably slain under the Old Covenant were told to wait a little while until their brethren, presumably believers in Jesus, would be slain as they were. So, the things in the Holy Place, at least at times, were occurring at the same time as events seen in the Most Holy Place.
It may be difficult to lay aside what one has been told about this book. Nevertheless, a willingness to consider a different point of view, and testing it alongside what one has been taught, might be seen as testing the truth in the sense that what remains after the fire would be most precious (1Corinthians 3:10-15). I’ve tried to test everything I believe alongside of what others say. Sometimes I’ve learned something new, while at other times I proved what I held as the truth was worthy of the name. I agree it is difficult to do, but I believe it is worth the risk.