Who Are the 'Souls Under the Altar' Mentioned in Revelation 6:9-11?
Some have claimed that these verses prove the immortality of the soul and that people go to heaven when they die. The Bible itself, however, shows that souls are mortal by nature (Job 33:22; Ezekiel 13:19; 18:4, 20) and that this entire description is symbolic, not literal.
What did John see? In vision he beheld a book or scroll sealed with seven seals. As Jesus opened each seal (Revelation 5:5), John saw a preview of an event that would "take place after this" (Revelation 4:1). John was "in the Spirit" while the seven seals were being opened (verse 2). So, the events he saw were not actually happening then; he saw heavenly enactments of what was to take place in the future on earth.
When the fifth seal was opened, John "saw under [at the base of] the altar the souls of those who had been slain" (Revelation 6:9). Because Jesus revealed the meaning of the seven seals when He was on earth, we know that the fifth seal is symbolic of the coming Great Tribulation (Matthew 24:9-28). This means that Revelation 6 reveals an event to take place on the earth just before Christ's return.
In vision, John is projected forward to our time now, a time when one martyrdom has already happened (during the Middle Ages) and a greater one (the Tribulation) is yet to come. The "souls" (Christians) who "would be slain [martyred]" are told to "rest a little while longer, until both the number of their fellow servants and their brethren, who would be killed as they were, was completed" (Revelation 6:11). Those who have died as martyrs are to continue to "rest" - remain in their graves (compare Acts 2:26-27) - until others, like them, are also martyred. Remember, heaven contains no graves, so this must occur on the earth.
The "souls" - the dead saints - crying "avenge our blood" (Revelation 6:10) is similar to Abel's blood (his life, see Leviticus 17:14) crying to God from the ground (Genesis 4:10; Hebrews 11:4). Since neither blood nor the dead talk (Psalm 115:17; Ecclesiastes 9:5, 10), we know that the meaning is not literal. The "souls under the altar," then, is a symbolic picture of the martyrdom of saints.