Adam Clarke on Matthew 24:12

The love of many shall wax cold - By reason of these trials and persecutions from without, and those apostasies and false prophets from within, the love of many to Christ and his doctrine, and to one another, shall grow cold. Some openly deserting the faith, as Mat 24:10; others corrupting it, as Mat 24:11; and others growing indifferent about it, Mat 24:12. Even at this early period there seems to have been a very considerable defection in several Christian Churches; see Gal 3:1-4; 2Thes 3:1, etc.; 2Tim 1:15.