A person who acts contrary to God’s Word is not justified because he has acted according to his conviction. He is condemned. The thoughts, the intentions, the principles which each person has by nature are the very things from which every person must be converted, if he wants to be saved. Not the convictions of our natural reason as to what is good and evil, and wherewith one can stand before God, avails before God, but the conviction which God gives through His Holy Spirit (Walther, “Old Standard Gospels”, p. 177).
The office and function of the Holy Spirit are that he makes clear to us Christ and his work in our hearts, that he makes alive for us everything that Christ has taught us, spoken to us, done and suffered for us, that he makes Christ, his person, his work alive in our hearts, that he renders Christ intelligible to our hearts. Indeed, faith in the Lord Jesus Christ is an inner, divine thing. If the hand of the Holy Spirit does not enlighten our spirit, Christ is and remains a dead image, the Gospel of Christ for us [is] a bunch of dead letters. We need this Instructor. We need this pronouncement, this revelation which the Holy Spirit gives us.
The Holy Spirit reveals to us all the more the mystery of God, the mystery of Christ. By nature we have foolish, erroneous concepts of God. The Holy Spirit gives light through the Word. The Holy Spirit shows our spirit the Son and the Father whom Christ has proclaimed. The Holy Spirit puts a bright light into our hearts so that we in the countenance of this man Jesus Christ see the brightness of God, so that we see the Son and in him the Father. This same Spirit teaches us to call no one but Jesus Christ Lord, puts the name of Christ, the only-begotten Son, into our hearts, on our lips, so that we confess with our hearts that Jesus Christ is Lord, and wish such confession at the same time worship the Father in spirit and in truth.
The Holy Spirit alone reveals to us the mystery of the atonement and redemption which have come through Jesus Christ. By nature we have false, foolish concepts about the way of salvation. When we follow our own impulse, we always mix our own works into faith. We always want to add a little something to what Christ has done. The Holy Spirit teaches and assures that our every work is a matter vain, lost, and condemned, that Christ’s work, Christ’s death, Christ’s way to the Father is our only righteousness, that Christ stands in our stead, that Christ has without our aid accomplished all things for us. The Holy Spirit causes the comfort of redemption to sink into our heart and makes divinely sure that the prince of this world, that sin, death, hell are really judged and condemned. The Holy Spirit draws Christ, his work and merit, into our heart, that we confess from our hearts, each one for his own self: This Jesus is my Savior, who has borne all my sin. God is gracious to me through Christ, his Son (George Stoeckhardt, “Grace Upon Grace”, p. 203-204).