6:19 Say: "What thing is most weighty in evidence?" Say: "Allah is Witness between me and you: this Qur'an hath been revealed to me by inspiration that I may warn you and all whom it reaches. Can ye possibly bear witness that besides Allah there is another god?" Say: "Nay! I cannot bear witness!" Say: "But in truth He is the One Allah and I truly am innocent of (your blasphemy of) joining others with Him.
Help your brother when he is oppressed. (Bukhari & Tirmizi)