"Free will" (power to make all moral choices) is not a Biblical notion, it is a philosophical notion (Aristotle, Cicero) introduced by Pelagius (British monk around 400 AD) on the assumption that it is required for the moral responsibility of man. Biblically, this is not so.
I don't know enough historically to say too much, but I think free will was something the Early Church Fathers held. At least FutureAndAHope in this other thread claimed the Early Church believed in free will.
And the Early Church Fathers, note this is only a few quotes, the early Church Fathers are full of like references.
Irenaeus in his Against Heresies - Book 4 Ch 35-38
Chap. XXXVII. — Men Are Possessed of Free Will, and Endowed with the Faculty of Making a Choice. It Is Not True, Therefore, That Some Are by Nature Good, and Others Bad.
1. This expression [of our Lord], “How often would I have gathered thy children together, and thou wouldest not,” (Mat 23:37) set forth the ancient law of human liberty, because God made man a free [agent] from the beginning, possessing his own power, even as he does his own soul, to obey the behests (ad utendum sententia) of God voluntarily, and not by compulsion of God. For there is no coercion with God, but a good will [towards us] is present with Him continually. And therefore does He give good counsel to all….
…. And not merely in works, but also in faith, has God preserved the will of man free and under his own control, saying, “According to thy faith be it unto thee;” (Mat 9:29) thus showing that there is a faith specially belonging to man, since he has an opinion specially his own. And again, “All things are possible to him that believeth;” (Mat 9:23) and, “Go thy way; and as thou hast believed, so be it done unto thee.” (Mat 8:13) Now all such expressions demonstrate that man is in his own power with respect to faith. And for this reason, “he that believeth in Him has eternal life while he who believeth not the Son hath not eternal life, but the wrath of God shall remain upon him.” (Joh 3:36) In the same manner therefore the Lord, both showing His own goodness, and indicating that man is in his own free will and his own power, said to Jerusalem, “How often have I wished to gather thy children together, as a hen [gathereth] her chickens under her wings, and ye would not! Wherefore your house shall be left unto you desolate.” (Mat 23:37, Mat 23:38)
And so Does David Bercot, who has studied the Early Church for half his life.
"The early Christians were strong believers in free will. For example, Justin Martyr made this argument to the Romans: We have learned from the prophets, and we hold it to be true, that punishments, chastisements, and rewards are rendered according to the merit of each man's actions. Otherwise, if all things happen by fate, then nothing is in our own power. For if it is predestined that one man be good and another man evil, then the first is not deserving of praise or the other to be blamed. Unless humans have the power of avoiding evil and choosing good by free choice, they are not accountable for their actionswhatever they may be.... For neither would a man be worthy of reward or praise if he did not of himself choose the good, but was merely created for that end. Likewise, if a man were evil, he would not deserve punishment, since he was not evil of himself, being unable to do anything else than what he was made for.
Clement echoed the same belief: Neither praise nor condemnation, neither rewards nor punishments, are right if the soul does not have the power of choice and avoidance, if evil is involuntary.
Archelaus, writing a few decades later, repeated the same understanding: All the creatures that God made, He made very good. And He gave to every individual the sense of free will, by which standard He also instituted the law of judgment.... And certainly whoever will, may keep the commandments. Whoever despises them and turns aside to what is contrary to them, shall yet without doubt have to face this law of judgment.... There can be no doubt that every individual, in using his own proper power of will, may shape his course in whatever direction he pleases.
Methodius, a Christian martyr who lived near the end of the third century, wrote similarly, Those [pagans] who decide that man does not have free will, but say that he is governed by the unavoidable necessities of fate, are guilty of impiety toward God Himself, making Him out to be the cause and author of human evils.
The early Christians weren't simply speculating about this matter, but rather they based their beliefs on the following Scriptures, among others:
For God so loved the world that He gave his only begotten Son, that whoever believes in Him should not perish but have everlasting life (John 3:16).
The Lord is not slack concerning His promise, as some count slackness, but is longsuffering toward us, not willing that any should perish but that all should come to repentance (2 Pet. 3:9).
The Spirit and the bride say, Come!' And let him who hears say, Come!' And let him who thirsts come. And whoever desires, let him take the water of life freely (Rev. 22:17).
I have set before you life and death, blessing and cursing; therefore choose life, that both you and your descendants may live (Deut. 30:19).
So originally, it was the pagan world, not the Christians, who believed in predestination."
From Will the Real Heretics Please Stand Up
by David Bercot