The following was written in partial fulfillment of the requirements of Dr. Steve McKinion's Christian Theology II class at Southeastern Baptist Theological Seminary.
What role does the Holy Spirit play in conversion?
The Holy Spirit is the member of the Triune Godhead who actively brings about our conversion. It is the Spirit who regenerates a person, indwells him, and seals him for the day of salvation. The spirit makes the gospel powerfully effective for salvation so that those who hear it may believe and be saved. On these points all are agreed, since they are backed by straightforward statements in Scripture. The particulars, however, are a matter of some controversy, and so bear further consideration.
There are two broad views of the Spirit’s work in regeneration. In the non- Calvinist view (whether Arminian, Roman Catholic, or variations thereon in other streams of Christian tradition), the Spirit does preparatory work in the hearts of the unregenerate and provides God’s grace to enable people to choose whether to respond to the gospel or not. However it is articulated (most commonly as “prevenient grace” in Baptist circles), this view emphasizes that the Spirit’s work is essential in making available the effects of Christ’s work on the cross to whomever will believe. Without the Spirit’s work, regeneration through faith is impossible, because no one will believe. With the Spirit’s work, men are enabled to choose freely whether to follow God or no.
In the Calvinist view, by contrast, the Spirit not only works in a preparatory sense, but is also the active agent in bringing about conversion. People choose as they will, and people dead in their trespasses always choose sin over God—this is the essence of our fallen nature. What is needed, in this view, is not only the grace-given ability to choose (as in a prevenient grace view) but a grace-changed heart so that we will freely choose God. No matter how free our choice, unless the effects of original sin in us are undone, we continue freely to choose sin and to reject God. The Spirit, then, takes away hearts of stone and gives instead beating hearts of flesh that can respond to God. He gives eyes to see the light he shines as well as the light itself.
The essential disagreement between the two views is to whom the Spirit gives such eyes: to all men who hear the gospel, or only to the elect. Based on Paul’s arguments in 1 Corinthians, Ephesians, and elsewhere, I take it to be the latter. If the Spirit opened everyone’s eyes to see truly the goodness of God, if he gave to everyone hearts of flesh rather than hearts of stone all would believe. Regeneration logically precedes (but temporally coincides with) faith: the unregenerate heart cannot and does not believe. So the Spirit gives hearts that can and do believe, and in that very moment, we believe. The Spirit gives us not only the opportunity to exercise faith, but also the faith that we exercise.
However the act of regeneration is accomplished, the Spirit is efficaciously at work. In both views, the gospel is powerful for salvation—whether by tilling the soil or by actually causing the seed to sprout. People hear the gospel and the Spirit uses that mightily. Then, once people have believed, the Holy Spirit continues to work. He immediately indwells the believer, giving our mortal bodies spiritual vitality. Thus Paul says that the same Spirit who raised Christ from the dead is now at work in all believers. This indwelling seals our conversion, ensuring we hold fast until we die or Christ returns. He increasingly shapes our behaviors and attitudes to be more in line with those of God, making us holy as God is holy.
In short, the Spirit is the one who makes Christ’s work effective for salvation. He enables and empowers the gospel to produce conversion.