Simply put, prevenient grace is the grace of God given to individuals that releases them from their bondage to sin and enables them to come to Christ in faith but does not guarantee that the sinner will actually do so. Thus, the efficacy of the enabling grace of God is determined not by God but by man.
Historically, within the Arminian theological system, there have been three prominent positions concerning the doctrine of prevenient grace. Within classical Arminianism, there are two positions. Within Wesleyanism, there is one prominent position. Though all three positions have similarities, they are by no means identical. In fact, correctly defining prevenient grace has led to in-house debates within the Arminian tradition.
The first of the two prominent positions on the doctrine of prevenient grace in classical Arminianism is that until the Gospel, the instrument by which God draws sinners to Himself, is presented to a sinner, the sinner is in complete bondage to sin. The Holy Spirit works with the presentation of the Gospel through teaching (John 6:45) and convicting (John 16:8) the sinner, enabling the sinner to respond in the exercising of saving faith in Christ. The Holy Spirit opens the heart (Acts 16:14) and mind (Luke 24:45) of the sinner, thus drawing the sinner to Christ (John 6:44, 12:32), and the sinner is then enabled to exercise his newly freed will in placing his faith in Christ for salvation. This falls in line with the biblical teaching that the natural man is unable to understand spiritual things (1 Corinthians 2:14; Romans 8:7-8), which would include the message of the Gospel. However, Arminians teach that, although the sinner is now enabled to place his faith in Christ, this enablement by no means guarantees that the sinner will actually do so. This contradicts the proclamation by Jesus that all those the Father gives to Him will come to Him (John 6:37).
The second position is a bit more complicated than the first. In this position there is, essentially, a lesser and greater drawing via prevenient grace, which comes through the proclamation of the Gospel and the internal calling of God, sometimes referred to as the “full intensity” of prevenient grace. That is, God is drawing all men in a lesser sense and then drawing those who have the Gospel presented to them in another, greater sense. Some have called this latter drawing the dispensing of “particular prevenient grace.” In this position, God has given all men a prevenient grace that results in a universal healing of total depravity by the grace of God through the atoning work of Christ. This, in turn, has alleviated, though not fully, the corruption of inherited depravity. This position resembles what is sometimes called the “partial depravity” of Arminianism, since total depravity no longer describes what people are but rather what people were. That is, because of the atoning work of Christ, all people are no longer completely incapable of hearing and responding to the Gospel (John 6:44, 8:43); rather, all people have some ability. However, similar to the other position in classical Arminianism, people are not completely freed from their bondage of sin until the Gospel is presented to them and God calls them internally through its presentation. Arminius might have referred to this concept when he spoke of the “intermediate stage between being unregenerate and regenerate” while others have referred to people in this stage as “partially regenerated.” Since Arminians believe that regeneration logically comes after faith, when a person repents of his sin and exercises saving faith in Christ, then that person is “fully regenerated.”
The last position on the doctrine of prevenient grace is that of the Wesleyans (also known as Wesleyan-Arminians). In this position, because of the first coming and atoning work of Christ, God has dispensed a universal prevenient grace that fully negates the depravity of man. Thus, man is now in a neutral state. Those who adhere to this position assert that because of Christ’s promises that speak of “all men” being drawn (John 12:32) and the “world” being convicted (John 16:8) after His sacrifice, it means that the prevenient grace we experience today was something purchased by Christ’s work on the cross. Since Wesleyans believe in unlimited atonement as opposed to limited atonement, Wesleyans then further state that when Paul speaks of God giving those whom Christ died for “all things” (Romans 8:32), this universal prevenient grace is one of those “all things.” ( From a four point calvinst source )