John Gill emphasizes the significance of the anointing believers receive from Christ, the Holy One, which equips them with the Holy Spirit's graces. This anointing is likened to the oil used in the Old Testament, symbolizing the continuous grace that flows from Christ to His followers. Gill explains that this divine unction grants believers insight and understanding, enabling them to discern truth from error and recognize the mysteries of the Gospel. He reassures that while believers may not possess complete knowledge, they are empowered to understand spiritual truths necessary for salvation. Ultimately, this anointing affirms their identity as true Christians, set apart by God's grace.

Ver. 20. But ye have an unction from the Holy One,.... Meaning the Spirit, and his graces, with which Christ, the head, is anointed without measure, and his members in measure; from whence he is called Christ, and they Christians. These were really the Lord's anointed ones; they were true believers; were the wise virgins who had oil in their vessels with their lamps, which would never go out. The grace of the Spirit is called a chrism, or an ointment, or an anointing, in allusion to the anointing oil under the law; See Gill on "Mt 25:3"; of which anointing oil the Jews say {h}, that it continues all of it, awbl dytel, "to time to come", (i.e. to the times of the Messiah,) as it is said, Ex 30:31. Now this these saints had, "from the Holy One"; or that Holy One; meaning, not the Holy Spirit of God, though it is true that this anointing, or these graces, were from him; he is the author of them, and may truly be said to anoint with them; nor the Father, who is holy in his nature, and in his works, and is the God of all grace, and is said to anoint the saints too, 2Co 1:21, but rather the Lord Jesus Christ, who is holy, both as God and man, and from whose fulness all grace is had. This oil, or ointment, was first poured on him without measure, and from him it descends to all the members of his mystical body, as the ointment poured on Aaron's head descended to his beard, and to the skirts of his garments; see 1Jo 2:27; and ye know all things; for this anointing is a teaching one; it makes persons of quick understanding; it enlightens their understandings, refreshes their memories, and strengthens all the powers and faculties of the soul; it leads into the knowledge of all spiritual things, into all the mysteries of grace, and truths of the Gospel, into all things necessary for salvation; for these words are not to be taken in the largest sense, in which they are only applicable to the omniscient God, but to be restrained to the subject matter treated of, and to those things chiefly in which the antichrists and deceivers cited; and regard not a perfect knowledge, for those that know most of these things, under the influence of this unction, know but in part. The Syriac version reads, "all men", and so refers to that discerning of spirits, of the Spirit of truth, from the spirit of error; a gift which was bestowed on many in the primitive times, by which they could distinguish hypocrites from true believers, and antichrists and deceivers from the faithful ministers of the word. One of Stephens's copies reads, "and ye all know". {h} T. Hieros. Horayot, fol. 47. 3.