This paper will make the case that πνευ̂μα in Jn. 6.63b is best interpreted contextually as the Holy Spirit, and that the statement has special significance in the Gospel’s seven sign structure and Spirit-Christology, such that it is key for how we receive the benefits of Christ’s work—feeding on his body and blood as true food and drink. John and Jesus in John tell us that we can only do this as we hear and receive the apostolic testimony-words (= Jesus’ testimony-words) by faith as life-giving Spirit-words. Only because we have the indwelling Holy Spirit, can we abide (continue on) in Christ and in his words. Equally, we can know the person and work of the Holy Spirit, and his ongoing life-giving, as we look to his words by faith.
This is to assert a kind of functional equivalency between the Spirit and his words, and warns us away from our tendency to separate the external, objective living and active word of God from the internal, subjective operation of the Spirit that is promised to accompany it if we receive it with faith. We have our real life (in Johannine terms, in its “eternal” and “abundant” quality) only from God, and specifically God the Spirit, yet we also live by every word which proceeds from the mouth of God (Deut. 8.3, part of the Passover and wilderness manna background of Jn. 6). This is how the Spirit works in us.
These points also suggest a retrieval of the Lutheran and Reformed emphasis on Spiritus cum verbo and the ordinary means of grace (word and sacraments). That tradition, with this Johannine support, offers practical help for ordinary Christians to know they can experience the Spirit and his work as they hear his clear and sufficient speaking in the Scripture.