1. What is the Sanctuary – what or who does it represent? Literally, the Sanctuary was the place to praise and worship God, make offerings to Him, etc. (Hebrews 9:2) In the spiritual sense, it is where God’s true children, His Church dwell. We dwell not in a place but our hearts and minds unite in communion with God and Jesus. We “are the temple of God and that the Spirit of God dwells in you…” 1 Corinthians 3:16. “…Your life is hidden with Christ in God.” Colossians 3:3.
  2. How did the Sanctuary come into a condition where it needed to be “cleansed”? Daniel 8:11 shows that the “regular” or “continual” sacrifice was removed, the foundation of the Sanctuary, supplanted by the “abomination of desolation” stated in Daniel 11:31. The foundation truth is Jesus died once for all to ransom all mankind. Hebrews 10:10, “…we are sanctified through the offering of the body of Jesus Christ once for all.” (Also 1 Timothy 2:4-6.) The “abomination” was the doctrine of the Mass, which re-sacrifices Jesus each time it’s performed. Along with this false practice were many others instituted over the centuries. 
  3. How and when did the cleansing of the Sanctuary take place? Daniel 11 and 12 show that the Sanctuary (true Church) was helped with the Great Reformation (Daniel 11:34). Then Napoleon Bonaparte helped to break the persecuting control religion had on the people (Daniel 11:36-45). Thus began the “Time of the End”. During this period, Daniel 8:19 states the cleansing would commence and be completed. The cleansing of the Sanctuary was complete in 1846 A.D. How do we know this? Many Bible Societies were formed in the early 1800s resulting in the ability to study the Bible freely which led to more reformation work. Precious truths were and continue to be uncovered. 
  4. The 2,300 “days” – what is that timeline? 2,300 “days” is not literal, but prophetic using “each day for a year”, Numbers 14:34. So this would indicate 2,300 years. In the 70 weeks prophecy of Daniel 9:21-27, there is a clue regarding the beginning of these 2,300 years. The 70 weeks is a prophetic timeline of 490 years. From Daniel 9:25 we see that the 70 weeks of 490 years began with the decree to rebuild and restore Jerusalem, and ended with the destruction of Jerusalem in 69/70 A.D. Artaxerxes issued a decree to Nehemiah (Nehemiah 1:1-2:8) to go and rebuild and restore Jerusalem in 454 B.C. Thus, the 2,300 years stretched from 454 B.C. to 1846 A.D.

For an extensive, in-depth study of the Cleansing of the Sanctuary, use the following link: http://www.mostholyfaith.com/Beta/bible/volumes/C04.asp