What is the evidence for stipulating observing loyalty as well as disassociation for the sake of Allah in the Quran and the Prophetic Sunnah?

{ O you who have believed, do not take the Jews and the Christians as allies. They are [in fact] allies of one another. And whoever is an ally to them among you - then indeed, he is [one] of them. Indeed, Allah guides not the wrongdoing people ... Your ally is none but Allah and [therefore] His Messenger and those who have believed ... }

{ 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.}