Ye - emphatical: YE who confess Jesus: in contrast to “them,” the false teachers.
overcome them - (1Jo 5:4, 1Jo 5:5); instead of being “overcome and brought into (spiritual) bondage” by them (2Pe 2:19). Joh 10:8, Joh 10:5, “the sheep did not hear them”: “a stranger will they not follow, but will flee from him: for they know not the voice of strangers.”
he that is in you - God, of whom ye are.
he that is in the word - the spirit of Antichrist, the devil, “the prince of this world.”