“They will do this
Because they have not known
καὶ ταῦτα ποιήσουσιν ὅτι οὐκ ἔγνωσαν τὸν Πατέρα οὐδὲ ἐμέ.
John uniquely indicated that Jesus said that they would do this (καὶ ταῦτα ποιήσουσιν), that is try to kill them, because they have not known (ὅτι οὐκ ἔγνωσαν) the Father (τὸν Πατέρα) nor Jesus (οὐδὲ ἐμέ). Jesus said that these persecutors of his followers had no idea about Jesus and God, the Father. They were stuck on their God, Yahweh. If they had known about God, the Father, and Jesus, his Son, they would not have done this. Do you know about God, the Father, and his Son, Jesus?