Quran 5:51 — The Feast (Al-Ma'edah)

O you who believe, do not take certain Jews and Christians as allies; these are allies of one another. Those among you who ally themselves with these belong with them. GOD does not guide the transgressors.

[5:50] Is it the law of the days of ignorance that they seek to uphold? Whose law is better than GOD's for those who have attained certainty?

[5:52] You will see those who harbor doubt in their hearts hasten to join them, saying, "We fear lest we may be defeated." May GOD bring victory, or a command from Him, that causes them to regret their secret thoughts.