In Romans chapter 5 and 6, Paul has explained how man was a slave to sin, which means he is in slavery, is in chains, is in captivity, can not do what he wants, has to do what his “master”, sin, wants him to do. And then he is released.
So then he is free! Except that…17 “But thanks be to God, that though you were slaves of sin, you became obedient from the heart to that form of teaching to which you were committed.” 18 “And having been FREED from sin, you became slaves of righteousness.
Note how Paul switches from slavery to one thing, sin, to slavery to another thing, righteousness. First his will is serving sin, which is his master, and then it is serving righteousness, his NEW master.
So when did Paul ever have the freedom of his own will? “..having been taken captive by him (devil) to do his will”. And “once I was alive apart from law, but when law came,sin revived and I died…”
So all of his (sinful) life, he never had a “free” will at all!
He further explains in chapter 7 how he has had the desire to do good in his mind, [in accordance with law] but his resolve never saw the light of day, there is no practical ACTUAL result of righteousness, because as already expressed, there is something in him that prevents him from carrying out that good intention that his mind was aware of. [Of Jesus it was said, “for he knew what was in man”.]
He is explaining how the law brought him into the captivity of sin, by bringing to him knowledge of his guilt, from which he cannot escape. It is not possible for one who is guilty, to operate with a free conscience, and this is what “thwarts” his will. The end result is that he fails, and sin results. [his only “outworking” is an expression of a mediocrity that falls far below the expectation of the Spirit]. So he explains how man [under law] is “wretched” in captivity to sin. He is “under the wrath of God.” [“For the sting of death is sin, and the power of sin is the law”.] The law gives the flesh its power to accuse.
Into this situation he is about to bring Christ’s victory (chapter 8) by which he is freed from sin and enters “captivity” by his now freed will, to the service of righteousness. He willingly and gladly enters into the “servitude” of Christ. “Eager to do what is right”.
So chapters 5 & 6 were stating the facts of captivity and release from slavery to sin, [through the law] and chapter 7 explains the reality of it.
So man can never have a “free” will while his conscience is bound to sin. And it is only the free will that can serve God “freely”.
The original “freedom of will” was lost in the garden of Eden when Adam entered the service of the diabolos or accuser, the “devil”.
The only men that have freewill then, are Christians who have chosen to accept Jesus, and with that freed will they do the works of righteousness that the Spirit dictates. Whereas the rest of mankind who may think they have freewill, are really only producing what the desire of their flesh dictates to them.
(See ch.7 v.20 “But if I am doing the very thing I do not wish, I am no longer the one doing it, but sin which dwells in me”. (he [his will] is not in control) v 24 “wretched man”.)
[See also ch. 4 v15, ch. 6v14 ch. 6 verses 17,20, 22. ch,7 v6, 23,24. ]