What is the meaning of Matthew 24:11-12?

11 And many false prophets shall rise, and shall deceive many. 12 And because iniquity shall abound, the love of many shall wax cold. (Matthew 24:11-12 KJV)

Spurgeon’s Commentary on Matthew

Verse 11-12. What could not be accomplished by persecutors outside the Church, and traitors inside, would be attempted by teachers of heresy: “Many false prophets shall rise, and shall deceive many.” They have risen in all ages; in these modern times they have risen in clouds, till the air is thick with them, as with an army of devouring locusts. These are the men who invent new doctrines, and who seem to think that the religion of Jesus Christ is something that a man may twist into any form and shape that he pleases. Alas, that such teachers should have any disciples! It is doubly sad that they should be able to lead astray “many.” Yet, when it so happens, let us remember that the King said that it would be so. Is it, any wonder that, where such “iniquity abound” and such lawlessness is multiplied, “the love of many shall wax cold “? If the teachers deceive the people, and give them “another gospel which is not another”, it is no marvel that there is a lack of love and zeal. The wonder is that there is any love and zeal left after they have been subjected to such a chilling and killing process as that adopted by the advocates of the modern “destructive criticism.” Verily, it is rightly named “destructive “, for it destroys almost everything that is worth preserving.