The phrase went out from, may mean either removal (Rev 18:4; Joh 8:59) or origin (Rev 9:3; Rev 14:13, Rev 14:15, Rev 14:17; Rev 19:5, Rev 19:21). Here the latter, as appears from the following clause. Compare Act 20:30.
Were not of
See on Joh 1:46.
No doubt
A needless addition of the A.V.
With us (μεθ' ἡμῶν)
Ἑν ἡμῖν, among us, would be more according to John's ordinary usage; but his thought rests here rather on fellowship than on the unity of believers as one body.