Answer
The terms Provisionism and Provisionist are new by the standards of Christian theology. These labels have only been formally defined and used in the past few years. In broad terms, a Provisionist—someone who holds to Provisionism—holds a generally Arminian view of free will and salvation, with notable differences such as positive belief in eternal security. The main gist of Provisionism is the idea that the gospel is the Word of God, which is sufficient in itself, through the power of the Holy Spirit, to enable a response in all who hear God’s appeal to be reconciled to Him (John 6:63; Hebrews 4:12).
The clearest differences between Provisionist doctrine and classical Reformed theology are seen in the concepts of total depravity and limited atonement. The doctrine of total depravity suggests all people are inherently sinful, such that they could not even want to be saved without a direct, predestined act of God. Provisionism counters that all people are sinful and responsible for their sin, but they are also responsible for answering God’s universal call for men to be saved (Titus 2:11). Limited atonement is a doctrine teaching that Christ only died for those God had designated as the elect. A Provisionist would reject this, saying that the Bible teaches that Christ died for all people (1 John 2:2), which is why God promises to save any who come to Him in faith (Romans 10:11–13; Revelation 22:17). The Provisionist holds that Christ genuinely desires all of humanity to be saved (Luke 5:32; 19:10; 1 Timothy 2:4–6; ).
In effect, this means a Provisionist would also reject other Reformed doctrines such as irresistible grace.
The main use of the term Provisionism comes from the writings of theologian Leighton Flowers. The term is also meant to describe the general approach to salvation held by most Southern and Independent Baptists. So far as Reformed doctrine is concerned, this means narrow disagreement on the subjects of total depravity and limited atonement, as well as the exact meaning of words like predestined and elect.
Similar to the TULIP in Calvinism, Provisionism can be summarized with the acrostic PROVIDE (see https://soteriology101.com/about-2/statement-of-faith for more information):
People sin: Which separated all from fellowship with God.
Responsible: Able-to-respond to God’s appeals for reconciliation.
Open door: For anyone to enter by faith. Whosoever will may come to His open arms.
Vicarious atonement: Provides a way for anyone to be saved by Christ’s blood.
Illuminating grace: Provides clearly revealed truth so that all can know and respond in faith.
Destroyed: For unbelief and resisting the Holy Spirit.
Eternal security: For all true believers.
Christians have often debated the finer points of how human will and God’s sovereignty interact when it comes to salvation. Though the nuances of Provisionism may not be accepted by particular believers, its tenets are well within the realm of orthodox Christian theology.