History of Free Grace Theology

400-700ad

Augustine of Hippo and Bede in their comments imply that they were aware of Free grace theology, Augustine himself wrote a whole treatise against it, and in his book "Handbook on Faith, Hope and Love" Augustine mentions that this position was held among "Catholics" (which was a term used for those not seen as under God's curse, the term was not used for the Roman Catholic church which did not exist yet):

      " There are some, indeed, who believe that those who do not abandon the name of Christ, and who are baptized in his laver in the Church, who are not cut off from it by schism or heresy, who may then live in sins however great, not washing them away by repentance, nor redeeming them by alms—and who obstinately persevere in them to life's last day—even these will still be saved, "though as by fire." They believe that such people will be punished by fire, prolonged in proportion to their sins, but still not eternal. But those who believe thus, and still are Catholics, are deceived, as it seems to me, by a kind of merely human benevolence"

Though Augustine (354 - 430) implies they believed in Baptismal regeneration (which might be a misunderstanding on his part, as they could have meant "spiritual baptism"), they still taught that being "carnal" does not mean that one cannot be saved. 

After Augustine, they were mentioned by Bede (672 - 735), saying: 

    "Although the apostle Paul preached that we are justified by faith without works, those who understand by this that it does not matter whether they live evil lives or do wicked and terrible things, as long as they believe in Christ, because salvation is through faith, have made a great mistake. James here expounds how Paul's words ought to be understood. This is why he uses the example of Abraham, whom Paul also used as an example of faith, to show that the patriarch also performed good works in the light of his faith. It is therefore wrong to interpret Paul in such a way as to suggest that it did not matter whether Abraham put his faith into practice or not. What Paul meant was that no one obtains the gift of justification on the basis of merit derived from works performed beforehand, because the gift of justification comes only from faith. (Concerning the Epistle of St. James)"

Bede thus implies he knew some who argued, that because Paul said we are saved by faith alone, our works cannot later be a part of salvation.

Chrysostom (347 –  407) perhaps also tries to answer objections from some teaching Free grace theology: 

    "He that believeth on the Son, is not judged." He that "believeth," not he that is over-curious: he that "believeth," not the busybody. But what if his life be unclean, and his deeds evil? It is of such as these especially that Paul declares, that they are not true believers at all"

Medieval

It is plausible that the Brethren of the Free Spirit were Free grace, however all sources we have of them are hostile so we cannot know how much is true. They were accused of antinomianism and "rejecting the sacraments", which may refer to teaching justification by faith alone and opposing Baptismal regeneration, however they are more ambiguous, and we cannot know what they clearly taught.

The Reformation

Nicolaus von Amsdorf (1483 – 1565) was a Lutheran advocate of Free grace theology, he argued against Melanchton and George Major, who argued that if one does not have works they cannot be saved, Nicolaus stated thus against Major: 

    “All those who teach and write that good works are necessary for salvation are going directly against Luther, yes, directly against themselves. For Luther of blessed and holy memory writes everywhere and especially on Galatians that good works not only are not necessary for salvation, but are also harmful to salvation”

Nicolaus von Amsdorf

Some have taken Nicolaus' statement "but are also harmful to salvation", to mean that he was against good works in total, however he is referring to good works being harmful to salvation in the sense that works based salvation is harmful.

Additionally, Leupold Scharnschlager indicates that he was aware of Free grace theology:

    “No one can claim that faith, which comes from the preaching of God’s word, is merely a historical or dead faith, without effect or fruit. No doubt that is what people held at the time of James…Even today some understand Christ and Paul as ascribing righteousness and life to faith alone, as if a faith without deeds and fruit is enough for salvation. For how can it be a barren, that is, a dead faith, when life—and much more—comes forth from it?”

Later Protestants

Free grace theology was similar to the teachings of Robert Sandeman and the "Antinomians" of the 17th century, however Sandeman more closely represents a Free grace position held by Bob Wilkin and Hodges, denying the trust aspect of true faith (which I hold is an error).  Cotton, an advocate of the "Antinomian" side, said thus: 

John Cotton

    "Trulie it is hard to perceive [between a temporary believer and a true believer] when men differ, and therefore it is not an easie matter to make such use of sanctification, as by it to beare witnesse unto justification"

Cotton taught the doctrine of assurance, denying that good works are necessary for our assurance, and allowed for a true Christian to be almost indistinguishable from a false professor.

The Marrow Brethren of the 18th century weren't Free grace, however their doctrines have multiple similarities to Free grace, for example they denied that repentance of sin was necessary to come to Christ, however they argued it would happen instantly after one is justified. The Marrow Brethren also had an emphasis on assurance in Christ, though they allowed good works as subordinate proofs. The Marrow position on assurance in substance is the same as Charles Ryrie proposed. 

John Colquhoun (1748-1827), though working with a false definition of repentance (holding that it means turning away from sins), denied that it is necessary to be saved, thus in essence agreeing with Free grace theologians that one doesn't have to turn from their sins to be saved, though he might have differed semantically:

    "How then can his repentance atone for his iniquities, or entitle him to the favour of God and to the happiness of heaven? How can that evangelical repentance, which he is incapable of exercising till after his sins be all forgiven on the ground of an infinite atonement imputed to him, make atonement for them? How can that true repentance, which he cannot exercise until in justification he be already entitled to eternal life, entitle him to eternal life? Does not the consummate righteousness of Jesus Christ, imputed for justification, entitle the believer fully to it? What need is there, then, that his repentance should entitle him? How can that exercise of repentance which is the consequence of pardon, afford a previous title to pardon? or that which is a part of eternal life be a ground of right to eternal life?"

—John Colquhoun, Evangelical Repentance  (1748-1827) 

19-21th centuries

Right before the Lordship salvation controversy, there were some who were promoting Free grace ideas.

C. I. Scofield taught a Free grace view of repentance, seeing it as a change of mind rather than a turning from sins, Scofield Reference Bible on Acts 17:30: "Repentance is the translation of a Greek verb metanoeō, meaning to have another mind, to change the mind, and is used in the N.T. to indicate a change of mind"

Scofield also taught the "rewards" interpretation, where passages some take to refer to salvation by works, are taken to refer to eternal rewards: "1 Corinthians 3:14. God, in the N.T. Scriptures, offers to the lost, salvation, and, for the faithful service of the saved, rewards. The passages are easily distinguished by remembering that salvation is invariably spoken of as a free gift (e.g. John 4:10; Rom. 6:23; Eph. 2:8, 9); while rewards are earned by works (Mt. 10:42; Lk. 19:17; 1 Cor. 9:24, 25; 2 Tim. 4:7, 8; Rev. 2:10; 22:12). A further distinction is that salvation is a present possession (Lk. 7:50; John 3:36; 5:24; 6:47), while rewards are a future attainment, to be given at the coming of the Lord (Mt. 16:27; 2 Tim. 4:8; Rev. 22:12)."

Lewish Sperry Chafer (1871 –1952)

Charles Henry Mackintosh wasn't entirely Free grace, however he protested against the doctrine of progressive sanctification, which means that "all true believers will progressively get holier", this is a doctrine taught by Lordship salvationists, where if one isn't spiritually growing, he isn't a true believer.

Free grace theology was also taught by Lewish Sperry Chafer, who clearly distinguished between the call to discipleship and the call to salvation, he would later influence Charles Ryrie who wrote against John Mcarthur.  

In the 20th century the most well known advocates of Free grace were Charles Ryrie and Zane Hodges, however the two had some differences from each other.

Free grace theology is today mostly held among Baptists, Plymouth Brethren and non-denominationals, most major theologians to teach the position graduated from Dallas theological seminary.