“But you have an anointing from the Holy One, and you know all things.”
John now turns to the heretical claims of his opponents. They claimed superior knowledge because they had received exclusive knowledge (gnosis).
The word “you” is emphatic. The idea is, “You in contrast to the Gnostics.”
have an anointing
The anointing refers to the Holy Spirit’s coming to indwell each believer (Jn 14:17; 15:26; 16:13; Lu 4:18; Ac 10:38; Ro. 8:9; 1 Co. 12:13; 2 Co 1:21-22). The Greek indicates that we “keep on having” the indwelling of the Holy Spirit. He permanently indwells the believer.
from the Holy One,
Verses 18 and 19 warned Christians of false religion. Now, John affirms that believers have protection against deception. They have the Holy Spirit to guard them against error. He is a safeguard for our souls. Jesus is the “Holy One” who imparts the Holy Spirit to those who believe in Christ.
False religion made claims about God. They viewed themselves as possessing superior knowledge of the Gnostics. The Holy Spirit judges this teaching by the spirit of truth. He is the detector of error. He illuminates each genuine Christian about truth.
The Holy Spirit illumines us as to what is true.
The Holy Spirit initially dwells in every believer at the moment of salvation. God never repeats this anointing. God also inducts each believer into the priesthood at the point of salvation once.
The purpose of the anointing of the Holy Spirit on the believer is that the Holy Spirit is a constant service to the Christian. The Holy Spirit performs all His work on the believer from the moment of His indwelling. One of these functions is the illumination to understand divine revelation.
Unadulterated knowledge of God’s Word without the enabling power to understand it is a futile exercise. Along with the factual knowledge of the objective Word of God, we need spiritual understanding. We need the Holy Spirit to receive, comprehend, and appropriate divine truth.