What is the Holy Spirit?
Actually, the question is not “what,” but “who.”  The Holy Spirit is Someone, not something.  A common error is to speak of the Holy Spirit as a neuter noun.  Christians have a tendency to speak of the Holy Spirit as an impersonal power or as some energy which takes hold of us.  Presbyterians believe that the Holy Spirit is a personal, conscious, thinking, willing Being.

So, Who is the Holy Spirit?
First of all, simply stated, the Holy Spirit is God.  Just as the Father is God, and just as Jesus Christ (the Son) is God, so also the Spirit is God.  The Holy Spirit is not some separate deity, but is a distinguishable expression of the one true God.  Also, the Holy Spirit is not a mere representation of God, expressing only a fraction of God’s being.  Rather, we believe that the wholeness of God is expressed in the Holy Spirit.

How does the Holy Spirit work?
Just as God the Father works beyond us as the Creator of the entire universe, and just as God the Son works for us as the Redeemer Who reconciles us to God; so also God the Holy Spirit works in us as the Sustainer of our lives with God’s grace.

Presbyterians believe that the Holy Spirit dwells within us—that our spirits and the Holy Spirit abide as one.  By the indwelling of the Spirit, we and God become one.  This is not to say that God’s identity and ours are the same.  The indwelling of the Holy Spirit means that, although we are distinguishable, we and God are inseparable.

We believe that our very lives are transformed by the Holy Spirit.  Because the Spirit of God now abides in us, we are endowed with the grace of God.  God’s grace is realized in us by the Holy Spirit, and we refer to this realized grace as spiritual gifts.

What does it mean to have life in the Holy Spirit?
In the Nicene Creed (one of our early Christian statements of faith), we affirm that, “We believe in the Holy Spirit, the Lord and Giver of Life.”  When we affirm that the Spirit of God is the Giver of Life, we mean more than just biological life (although this also is a gift from God).  Presbyterians believe that we do not truly have life until the Spirit of God is living in us.  The life which the Holy Spirit gives us is reconciliation to and fellowship with God Who is the source of all life—the foundation of our very being.

We are indeed reconciled to God through the work of Jesus Christ (the Son).  But, it is by the Holy Spirit that we receive the work of Christ as a gift.  The Spirit gives us the gift of faith so that we may respond to God’s gracious gift of reconciliation.  Paul expresses this point when he writes, “No one can say ‘Jesus is Lord’ except by the Holy Spirit” (1 Corinthians 12:3).

Our reconciliation with God is of such an intimate and loving nature that we come to know God as our Father and ourselves as God’s children.  Effectively, God offers us the gift of adoption and makes us His children by His Spirit.  We Presbyterians believe that the Holy Spirit adopts us a God’s children—children who live in a relationship which is as eternal as God Himself.  As Paul writes, “For all who are led by the Spirit of God are children of God.  When we cry, ‘Abba!  Father!’ it is that very Spirit bearing witness with our spirit that we are children of God, and if children, then heirs—heirs of God and joint heirs with Christ” (Romans 8:14-17).

What does it mean to have illumination in the Holy Spirit?
Literally speaking, “illumination” is the act or process of casting light upon a thing.  It is the act of making a thing visible so that it can be seen and known.  In a theological context, illumination is the process of making God known.  This illumination of God can be understood in two ways.  First, illumination can be understood as our casting light upon God—as our discovering God in nature, in Scripture, or in history.  Second, illumination can be understood as God casting light upon Himself—as God revealing Himself in nature, in Scripture, or in history.

Presbyterians believe that we cannot know God through discovery.  In order for God to be discovered, He must disclose Himself to us.  We believe that knowledge of God comes only through His own self-revelation.  We believe, therefore, that all knowledge of God is revealed knowledge and that the Holy Spirit is God illuminating Himself.

The Holy Spirit can reveal God to us in nature and in history.  We can see in nature the handiwork of God, and in history, we can see the mighty acts of God.  Without the illumination of the Holy Spirit, nature and history would be to us nothing more than meaningless, random phenomena or aimless events in time.

The Holy Spirit also reveals God to us in what we refer to as the Word of God.  The Word of God is God’s self-disclosure.  Insofar as Jesus Christ revealed God to the first disciples, Jesus is the Word of God.  And, insofar as Scripture reveals God to us, the Bible is the Word of God.  Presbyterians believe that the Holy Spirit reveals God to us in Scripture.  Through the written words of Scripture, the Holy Spirit speaks to us and makes God known just as He was made known to the first disciples of Christ.  Without the illumination of the Holy Spirit, the Bible would be to us just another book.

The Holy Spirit speaks the Word of God to us not only in Scripture, but also in the Sacraments.  We believe that, through the water of Baptism and the bread and wine of the Lord’s Supper, the Word of God is enacted.  Through the Sacraments, the Holy Spirit speaks within us and makes God known.  Without the illumination of God’s Spirit, the Sacraments would be to us nothing more than water, bread, and wine.

What does it mean to have fellowship in the Holy Spirit?
“There are a variety of gifts” and “to each is given the manifestation of the Spirit,” (1 Corinthians 12:4, 7).  With these words, the apostle Paul tells us that each individual receives respective gifts from the Spirit of God.  Yet, although these gifts may vary, it is the same Spirit Who gives them.  And, although these gifts are given to each individual, they are all given for the common good.

Presbyterians believe that the Spirit Who abides in one of us is the same Spirit Who abides in all of us.  We are thus united to one another in one Spirit.  The Holy Spirit is the life of the community of faith—the life of the body of Christ—the life of the Church.  In the Holy Spirit, we live in fellowship with one another.  In this fellowship, we belong to one another because we first belong to the Spirit of God.

We believe that when we pray to God for strength to serve Him and for help in times of trouble, God answers our prayers by giving us His Holy Spirit.  And, the Holy Spirit responds by giving us each other.  One person alone is not gifted with all that is needed to worship and serve God completely.  But, together, we have all the spiritual gifts needed to serve God’s will, to show God’s love, to glorify God, and to enjoy God forever.

This is what it means to have fellowship in the Holy Spirit.