In the name of Allaah the Most Merciful the ever Merciful "he guides whom he wills and misguides whom he wills" – to whom does the word "will" refer to: Allaah or the slave? Am I free or driven? Am I permitted to address someone as: "you are misguided"?

All perfect praise be to Allaah, The Lord of the Worlds.  I testify that there is none worthy of worship except Allaah, and that Muhammad, sallallaahu ‘alayhi wa sallam, is His slave and Messenger.

Firstly, since you said, "In the name of Allaah the Most Merciful the ever Merciful, 'he guides whom he wills and misguides whom he wills'" we understand that you want to refer to a Quranic verse. However, this wording is not mentioned in the Quran. Instead, the following wordings are mentioned (which mean):

• {Allaah sends astray [thereby] whom He wills and guides whom He wills.}[Quran 14:4]

• {But He causes to stray whom He wills and guides whom He wills.}[Quran 16:93]

• {For indeed, Allaah sends astray whom He wills and guides whom He wills.}[Quran 35:8]

• {Thus does Allaah leave astray whom He wills and guides whom He wills.}[Quran 74:31]

It is worth noting that Allaah The Almighty mentioned "stray" before guidance in these four verses. Shaykh Siddeeq Hasan Khaan argued that the word astray was mentioned before guidance because the former preceded the latter, as it is the original nature. Guidance, therefore, is accidental.

Secondly, it should be noted that the word "will" in the four verses refers to Allaah The Almighty, since He, The Almighty, is the only One Who directs man towards guidance or misguidance. In other words, the person whom Allaah The Almighty guides experiences His bounty, the person whom Allaah The Almighty misguides experiences His justice. In addition, Allaah The Almighty informed us that a person's closeness to guidance and striving to acquire it causes Allaah The Almighty to guide him to it.

He the Almighty Says (what means):

•        {And those who are guided - He increases them in guidance and gives them their righteousness.}[Quran 47:17]

•        {And those who strive for Us - We will surely guide them to Our ways. And indeed, Allaah is with the doers of good.}[Quran 29:69]

Thirdly, it should be noted that fate is the secret of Allaah regarding His creation, and that no one knows whom Allaah The Almighty has willed to be guided or left astray. Besides, the final stages of people's lives are hidden for us: i.e., man may spend his lifetime astray then his life may end with a good deed through which he will enter Paradise, and vice versa. In a Hadeeth (narration) on the authority of Ibn Mas‘ood the Prophet mentioned that a person may practice the deeds of the inmates of Hell, such as sins or the like, until he is about to enter it, then,  what was decreed for him takes effect and he acts accordingly by offering the deeds of the dwellers of Paradise, through which he will enter Paradise. Another person may practice the deeds of the dwellers of Paradise until he is about to enter it, then what was decreed for him takes effect and he acts accordingly by offering the misdeeds of the inmates of Hell, through which he will enter Hell. [Al-Bukhari and Muslim]

As for saying to someone "you are misguided," there is no blame on you if it is said to demonstrate the fact that this person is distant from the means of guidance and is not observing their faith, and you intend to alert and deter him. However, it will not be permissible if you say this to shame or discourage him. In a Hadeeth on the authority of Ibn Mas‘ood, the Prophet said that insulting a Muslim is wickedness and disobedience to Allaah and His Messenger while killing him is an act of disbelievers that may lead the killer to disbelief, and the punishment for this is severe. [Al-Bukhari and Muslim]

Allaah Knows best.