Revelation 6: 9 – 11: And when he had opened the fifth seal, I saw under the altar the souls of them that were slain for the word of God, and for the testimony which they held: And they cried with a loud voice, saying, How long, O Lord, holy and true, dost thou not judge and avenge our blood on them that dwell on the earth? And white robes were given unto every one of them; and it was said unto them, that they should rest yet for a little season, until their fellowservants also and their brethren, that should be killed as they were, should be fulfilled.
When God instructed Moses to build the tabernacle in the wilderness, it was designed with two altars. The first was the brazen altar of sacrifice in the Outer Court, and the second was the golden altar of incense in the Holy Place. These two altars although having symbolism in the life of Christ and the spiritual journey of the believer, yet they also represent dimensions or planes of existence in the unseen worlds. When John saw souls under the altar of the heavenly sanctuary, he was seeing a people connected with the brazen altar of sacrifice in the Outer Court. These souls under the altar that John saw were the Jews who had been killed during seven church ages as a consequence of their forefathers calling for Jesus’ blood to be upon them and their children (Matthew 27: 25).
All of these Jewish souls under the brazen altar died without the new birth because they did not believe on Jesus as being their Messiah, thus they did not receive the Spirit of Christ into their hearts, and so they are in the next dimension calling for revenge to be exacted upon those who had killed them. If the Spirit of Christ was in them, then they would have asked forgiveness upon their enemies who had wrongfully treated them.
Whilst John saw Jewish souls under the brazen altar of sacrifice, our prophet however had an experience of going beyond the Curtain of Time in 1960, and saw the theophanies of the saints under the golden altar of incense. These saints that the prophet saw are in their angelic bodies because only the redeemed have an angel in Heaven (Matthew 18: 10), and only a redeemed people with perfect love (not revenge) in their hearts can go to that place.
It is from these details that we learn some more about dimensions and worlds. The Outer Court represents the physical world, whilst the Holy Place represents the Region of the Blessed, and the Holy of Holies represents God Himself. The brazen altar having its position in the Outer Court shows that it is a dimension or holding place very close to this world, whilst the golden altar having its position in the Holy Place shows that it is connected with the Region of the Blessed in the sixth dimension.
Before Jesus opened up the seven seals in Matthew 24, He was firstly transfigured into a glorified state in Matthew 17, and Moses and Elijah stepped into this dimension and were seen with Him. Before the Bride could be taken up from this world, and before the seven seals were opened in 1963, God took the prophet beyond the Curtain of Time in 1960 and let him walk amongst the saints under the golden altar in the sixth dimension. It is because there were things in the Bible that needed to be revealed, and for those things to be interpreted, the prophet needed that experience of visiting the next world to interpret those things correctly. There was a mystery of two altars under the fifth seal, a mystery of souls under the brazen altar and of theophanies under the golden altar that could only be interpreted by the prophet visiting the unseen world.