Those who say that once a person is saved such is forever saved are either not reading their bibles properly or are intentionally dishonest.
Our text of the day explicitly contradicts that school of thought. As a matter of fact, the Holy Spirit says that in the last days, many people will depart from the faith; i.e. they will fall away from their faith in Christ.
The Lord Jesus while speaking about the signs of the last days also told us that the abounding level of iniquity and sin will cause the love of many for God to wax cold. The Lord concluded that remark with a warning that only those who endure till the end will be saved (Matthew 24:13)). Does it mean that many believers will not be saved in the end? Yes!
Multiple times in the book of Revelation Jesus said that only the overcomers will be rewarded. To the church in Smyrna, he said only those who overcome will not be hurt by the second death (Revelation 2:11). The second death is the lake of fire and it is for those whose name is not written in the Lamb’s book of life (Revelation 20:15; 21:8).