In a number of manuscripts, verse 40 states, “For whoever is not against us [instead of you] is for us [instead of you].” The suggestion that the choice of the word you would be the result of a harmonization with Luke 9:50 is incorrect: the majority of the manuscripts in fact speak there of us! Choosing you does not imply a great difference with the other choice (us). Those to whom Jesus speaks (you) are the ones who follow him: what matters is their being together with him. Essentially there is therefore little difference.1
40 For the one who is not against us is for us.