What is apostasy?
Apostasy is turning one's back on the revealed truth of Scripture. It is not something taught by the apostles; it is a terrible thing that most people do not understand. In context, it involves adulterating or perverting the true gospel, which places one in danger of being accursed.
Les teaches that apostasy is a terrible thing, and most people do not even know what it means. He says it has nothing to do with the apostles. Apostasy is turning the back on the revealed truth of Scripture; it is turning our back on the revealed truths of Scripture. In the surrounding passage, Paul writes by inspiration of the Spirit, warning that if anyone—even an angel from heaven—preaches any other gospel than the one received, let him be accursed. Paul was not speaking out of meanness or envy; the Spirit is emphasizing that adulterating and perverting the true gospel puts a person in danger of being accursed.