And every spirit that confesseth not ... - That is, this doctrine is essential to the Christian system; and he who does not hold it cannot be regarded either as a Christian, or recognised as a Christian teacher. If he was not a man, then all that occurred in his life, in Gethsemane, and on the cross, was in “appearance” only, and was assumed only to delude the senses. There were no real sufferings; there was no shedding of blood; there was no death on the cross; and, of course, there was no atonement. A mere show, an appearance assumed, a vision, could not make atonement for sin; and a denial, therefore, of the doctrine that the Son of God had come in the flesh, was in fact a denial of the doctrine of expiation for sin. The Latin Vulgate here reads “qui solvit Jesum,” “who dissolves or divides Jesus;” and Socrates (H. E. vii. 32) says that in the old copies of the New Testament it is written ὅ λίει τὸν Ἱησοῦν ho liei ton Hiēsoun, “who dissolves or divides Jesus;” that is, who “separates” his true nature or person, or who supposes that there were “two” Christs, one in appearance, and one in reality. This reading was early found in some manuscripts, and is referred to by many of the Fathers, (see Wetstein,) but it has no real authority, and was evidently introduced, perhaps at first from a marginal note, to oppose the prevailing errors of the times. The common reading, “who confesseth not,” is found in all the Greek manuscripts, in the Syriac versions, in the Arabic; and, as Lucke says, the other reading is manifestly of Latin origin. The common reading in the text is that which is sustained by authority, and is entirely in accordance with the manner of John.
And this is that spirit of antichrist - This is one of the things which characterize antichrist. John here refers not to an individual who should be known as antichrist, but to a class of persons. This does not, however, forbid the idea that there might be some one individual, or a succession of persons in the church, to whom the name might be applied by way of eminence. See the notes at 1 John 2:18. Compare the notes at 2 Thessalonians 2:3 ff.
Whereof ye have heard that it should come - See the notes at 1 John 2:18.