While reading through some of the major Reformed Confessions, I have found an interesting and clear statement regarding the issue of "free will", from the Second Helvitic Confession of 1566.
The Second Helvitic Confession (1566)
Chapter IX Of Free-Will, and so of Man's Power and Ability
1. We teach in this matter, which at all times has been the cause of many conflicts in the Church, that there is a triple condition or estate of man to be considered. First, what man was before his fall — to wit, upright and free, who might both continue in goodness and decline to evil; but he declined to evil, and has wrapped both himself and all mankind in sin and death, as has been shown before.
2. Secondly, we are to consider what man was after his fall. His understanding, indeed, was not taken from him, neither was he deprived of his will, and altogether changed into a stone or stock. Nevertheless, these things are so altered in man that they are not able to do that now which they could do before his fall. For his understanding is darkened, and his will, which before was free, is now become a servile will; for it serveth sin, not nilling, but willing — for it is called a will, and not a nill. Therefore, as touching evil or sin, man does evil, not compelled either by God or the devil, but of his own accord; and in this regard he has a most free will. But whereas we see that oftentimes the most evil deeds and counsels of man are hindered by God, that they can not attain their end, this does not take from man liberty in evil, but God by his power does prevent that which man otherwise purposed freely: as Joseph's brethren did freely purpose to slay Joseph; but that they were not able to do it, because it seemed otherwise good to God in His secret counsel.
3. But as touching goodness and virtues, man's understanding does not of itself judge aright of heavenly things. For the evangelical and apostolical Scripture requires regeneration of every one of us that will be saved. Wherefore our first birth by Adam does nothing profit us to salvation. Paul says, "The natural man receiveth not the things of the Spirit." etc (1 Cor. 2:14). The same Paul elsewhere denies that we are "sufficient of ourselves to think any thing as of ourselves" (2 Cor. 3:5).
4. Now, it is evident that the mind or understanding is the guide of the will; and, seeing the guide is blind, it is easy to be seen how far the will can reach. Therefore man, not as yet regenerate, has no free will to good, no strength to perform that which is good. The Lord says in the gospel, "Verily, verily, I say unto you, whosoever committeth sin is the servant of sin" (John 8:34). And Paul the apostle says, "The carnal mind is enmity against God; for it is not subject to the law of God, neither indeed can be" (Rom. 8:7)
5. Furthermore, there is some understanding of earthly things remaining in man after his fall. For God has of mercy left him wit, though much differing from that which was in him before his fall. God commands us to garnish our wit, and therewithal He gives gifts and also the increase thereof. And it is a clear case that we can profit very little in all arts without the blessing of God. The Scripture, no doubt, refers all arts to God; yea, and the Gentiles also ascribe the beginnings of arts to the gods, as the authors thereof.
6. Lastly, we are to consider whether the regenerate have free will, and how far they have it. In regeneration the understanding is illuminated by the Holy Spirit, that it may understand both the mysteries and will of God. And the will itself is not only changed by the Spirit, but it is also endued with faculties, that, of its own accord, it may both will and do good (Rom. 8:4)
Unless we grant this, we shall deny Christian liberty, and bring in the bondage of the law. Besides, the prophet brings in God speaking thus: "I will put my law in their inward parts, and write it in their hearts" (Jer. 31:33; Ezek. 36:27). The Lord also says in the gospel, "If the Son... make you free, ye shall be free indeed" (John 8:36). Paul also to the Philippians, "For unto you it is given in the behalf of Christ, not only to believe in Him, but also to suffer for His sake" (Phil. 1:29). And again, "Being confident of this very thing, that He which hath begun a good work in you will perform it until the day of Jesus Christ" (ver. 6). Also, "For it is God which worketh in you both to will and to do of His good pleasure " (Phil. 2:13).
7. Where, nevertheless, we teach that there are two things to be observed — first, that the regenerate, in the choice and working of that which is good, do not only work passively, but actively; for they are moved of God that themselves may do that which they do. And Augustine does truly allege that saying that "God is said to be our helper, but no man can be helped but he that does somewhat." The Mannichaeans did bereave man of all action, and made him like a stone and a block.
8. Secondly, that in the regenerate there remains infirmity. For, seeing that sin dwells in us, and that the flesh in the regenerate strives against the Spirit, even to our lives' end, they do not readily perform in every point that which they had purposed. These things are confirmed by the apostle (Rom. 7:13-26; Gal. 6:17).
9. Therefore, all free will is weak by reason of the relics of the old Adam remaining in us so long as we live, and of the human corruption which so nearly cleaves to us. In the meanwhile, because the strength of the flesh and the relics of the old man are not of such great force that they can wholly quench the work of the Spirit, therefore the faithful are called free, yet so that they do acknowledge their infirmity, and glory to whit at all of their free will. For that which St. Augustine does repeat so often out of the apostle ought always to be kept in mind by the faithful: "What hast thou that thou didst not receive? now if thou didst receive it, why dost thou glory as if thou hadst not received it?" (1 Cor. 4:7). Hitherto may be added that that comes not straightaway to pass which we have purposed, for the events of things are in the hand of God. For which cause Paul besought the Lord that He would prosper his journey (Rom. 1:10). Wherefore, in this respect also, free will is very weak.
10. But in outward things no man denies but that both the regenerate and the unregenerate have their free will; for man hath this constitution common with other creatures (to whom he is not inferior) to will some things and to nill other things. So he may speak or keep silent, go out of his house or abide within. Although herein also God's power is evermore to be marked, which brought to pass that Balaam could not go so far as he would (Numb. 24:13), and that Zecharias, coming out of the temple, could not speak as he would have done (Luke 1:22).
11. In this matter we condemn the Mannichaeans, who deny that the beginning of evil unto man, being good, came from his free will. We condemn, also, the Pelagians, who affirm that an evil man has free will sufficiently to perform a good precept. Both these are confuted by the Scripture, which says to the former. "God hath made man upright" (Eccl. 7:29); and to the latter, "If the Son therefore shall make you free, ye shall be free indeed." (John 8:36)
— Joel R. Beeke (ed.) & Sinclair B. Ferguson (ed.), Reformed Confessions Harmonized (Grand Rapids, MI: Baker, 2007), pp. 56-59
While later Reformed orthodoxy tends to more scholastic, this statement from the earlier Second Helvitic Confession should be easier to grasp and understand for the normal person.