O you who have believed, do not take your fathers or your brothers as allies if they have preferred disbelief over belief. And whoever does so among you - then it is those who are the wrongdoers.
[Qur’aan 9:23]
Allah has ordered us to stay away from those who disbelieve in Him even if they be our fathers and sons. He has forbidden us from taking them as allies and/or friends.
Allah says in Surah Al-Mujaadilah Verse 22
You will not find a people who believe in Allah and the Last Day having affection for those who oppose Allah and His Messenger, even if they were their fathers or their sons or their brothers or their kindred. Those - He has decreed within their hearts faith and supported them with spirit from Him. And We will admit them to gardens beneath which rivers flow, wherein they abide eternally. Allah is pleased with them, and they are pleased with Him - those are the party of Allah . Unquestionably, the party of Allah - they are the successful.
And if we disobey Him and take these disbelievers as our friends and/or allies we will from among the wrong doers.
The Verse is explicit evidence for the fact that Islam comes first even before the ties of kinship.
If our very own fathers, brothers, and children choose disbelief we are to distance ourselves from them and not take them as allies and/or friends.
Reference(s):
Tafsir Ibn Katheer
Volume 3 Page 363-364