Yeah, it’s pretty widely held among many Christians that everyone who died a believer went straight to Heaven. While that notion is quite comforting during times of death and burial, no scripture in the Bible supports this. Revelation 20 tells us that after we die (for those who don’t live during the Tribulation and 7 Trumpet period of Rev 6 and 7), the dead in Christ will rise up in the First Resurrection. Of these, there are two groups: the dead beheaded saints (Rev. 20:4) and the Great Multitude Saints of Rev 7:9-17, which will also include all of the dead saints from history. The Great Multitude saints will serve in God’s Temple, while the Beheaded saints will reign with Jesus 1,000 years, a period of time when those who miraculously survive all seven trumpets will learn the truth and live under the Kingdom of Jesus Christ. So then where do the saints who died in history go until the first resurrection? They are in a spiritual sleep state, like Jesus said of Lazarus before He raised Him from the dead (a prototype of the first resurrection). This is why we have sleep. Sleep is a reminder that we die, and will be awakened the next morning (Jesus being the true Morning Star, the King of the resurrection). Death is associated with darkness, hence why we sleep at night. There you have it. Stay in prayer.