Summary: The “falling away” has historically occurred.
Discussion: In this scripture, the Greek word for “falling away” is apostasia meaning apostasy. It is referring to leaving Bible truths.
The falling away started to occur even when the apostles were alive. Some Christians believed they were already reigning on earth as men. They wanted prestige, prosperity, power even before the Lord returned at His second advent. The Apostle Paul addressed this error in 1 Corinthians 4:8 (NIV): “Already you have all you want! Already you have become rich! You have begun to reign–and that without us! How I wish that you really had begun to reign so that we also might reign with you!”
Sadly, this apostasy or false doctrine grew until the “Christian” church became very powerful with clergy, priests, and bishops. These men gained wealth and status. This error developed into the Roman Catholic Church. Kings and emperors bowed before and honored the church. Clergy gained power in civil matters and became persecutors of sincere believers.
Jesus taught that His followers would not have worldly power, but would be hated by the world. John 15:19-20 (NIV), “…if you belonged to the world, it would love you as its own. As it is, you do not belong to the world, but I have chosen you out of the world. That is why the world hates you. Remember what I told you: ‘A servant is not greater than his master.’ If they persecuted me, they will persecute you (true Christians) also.”
During the time span of the Dark Ages, papacy’s persecutions were severe. They included confiscation of property, prison, torture, and burning at the stake whenever Catholic teachings weren’t being followed. A small sampling includes the following: in Languedoc, over 100,000 were killed in one day. Grotius lists 100,000 Belgic people as being martyred. There were the massacres of Merindol (thousands of men, women, and children murdered and 24 towns were destroyed), and Orange in 1562 (more thousands were slain with sword, thrown on the points of hooks and daggers, roasted over slow fires and tortured). It was a criminal offense to possess or read the Bible.
2 Thessalonians 2:10 says, “To those involved in this dying world he will come with evil’s undiluted power to deceive, for they have refused to love the truth which could have saved them.” (Phillips Translation)
2 Thessalonians 2:11 teaches us that God will send strong delusions.
Thus, the “falling away” has already happened. Christ is soon to establish His reign on earth! Let us rejoice.
For an in-depth study on Christ's second coming, read online: "Our Lord's Return"