The last sentence you quoted is the point.
Can you see anything here aspiring towards holiness? Or here? “Now the works of the flesh are obvious: sexual immorality, impurity, depravity, idolatry, sorcery, hostilities, strife, jealousy, outbursts of anger, selfish rivalries, dissensions, factions, envying, murder, drunkenness, carousing, and similar things. I am warning you, as I had warned you before: Those who practice such things will not inherit the kingdom of God!” (Galatians 5:19–21) (NET)
No, I don't see anything aspiring toward holiness there. I also don't see a statement, "We can will only according to our nature." I see a warning that if we choose to sin, we will not inherit the kingdom of God. Why warn us if we have zero capacity to resist temptation?
What was the point of the Adam and Eve story? Why did God create Eve last, after all the other animals? Did God create a male and female of every other species but then overlook to create a female human? Or was the whole point to get Adam to realize that he is not like all the other animals?
How do humans differ from animals? We can make moral choices. It doesn't mean we can make moral choices perfectly without help from above or that we can understand how to do or desire to do so to the point that would impress God, who is perfect.
It also doesn't make us animals before the Holy Spirit acts on us and angels after the Holy Spirit acts on us.[/QUOTE]
We can indeed decide to do right/wrong things, but the sinner apart from the work of the Holy Spiriting on them cannot freely decide to live for Jesus, and to get saved by Him, as our sin natures want to stay away from doing just that.
Paul is not stating that if we choose to now live godly we can inherit the Kingdom, its that we can and do that once saved by grace of God, as he is contrasting the works of the sinful flesh and the redeemed person now in Christ.