Will fall away.
They will betray
They will hate
καὶ τότε σκανδαλισθήσονται πολλοὶ καὶ ἀλλήλους παραδώσουσιν καὶ μισήσουσιν ἀλλήλους·
There is something similar in Mark, chapter 13:12, and in Luke, chapter 21:16, but they mention specific family members who were betraying them. Matthew only has the vague “they” betraying one another. Jesus warned them that many of his followers would fall away, stumble, or be scandalized (καὶ τότε σκανδαλισθήσονται πολλοὶ). They would betray or abandon each other (καὶ ἀλλήλους παραδώσουσιν), even hating and detesting one another (καὶ μισήσουσιν ἀλλήλους). This was a far cry from love your neighbor.