At conversion, the Spirit also takes up residence in the life of the believer (Rom 8:11). Now he lives, and has the capacity to walk, be led, and be filled by the Spirit (Gal 5:16, 18, 25; Eph 5:18). He has the Spirit of Christ (Rom 8:9) and thus, the mind of Christ (1 Cor 2:16). As the believer is conformed to the image of Christ through sanctification by the Spirit, he is given the proper thinking to have a wholehearted understanding and embracing of the Word as truth and gets to understand and know God better. His eyes are enlightened to know the truth more deeply (Eph 1:18).
This indwelling Spirit is the same Spirit of Truth who was promised by Jesus to teach His disciples all things, bring to their remembrance all that he had said, guide them into all truth, and declare the things to come (John 14:26; 16:13). It is difficult to determine how much of the Spirit’s work in their lives from these promises was limited to them and what aspects are normative for believers of all times. John himself includes some examples of how the apostles remembered what Jesus had said and understood the significance after His resurrection (John 2:19-22; 12:16; cf. 20:9). One can certainly see how this perfect memory would be important for writing the Gospels. His teaching them and guiding them into all truth could certainly explain the epistles. Further, declaring the things to come would explain Revelation. So, perhaps this is a promise for the apostles’ ministry and the process of inscripturation.
Yet, when the same writer, John, later addresses a church in 1 John 2:20, 27, he tells them that they have received an anointing from the Holy One and as a result, they know all things and they do not need to be taught. It would contradict the very letter John is writing if these were absolutely unqualified statements. The context would rather indicate that they know the truth about Jesus well enough not to be led astray by those who deny Him. If the anointing here is the Spirit, which is a reasonable conclusion, then believers are presumed to be taught the truth by Him and therefore know the truth, understand it well enough to believe it, and understand the significance of it so that they can obey it. So, the teaching ministry of the Spirit seems to be normative in relation to the truth already revealed.
