Prophet Abraham - 14:10
"Their messengers said: "Do you doubt Allah, Who created the heavens and the earth, and He calls you to forgive you your sins and gives you a certain period of time?"They said: "You are but men like us, and you want to turn us away from that which our forefathers used to serve. Bring us a clear authorization"."
Why a human messenger?
The Night Journey/17:95
"Say: "If there were angels inhabiting the earth, We would have sent to them an angel from heaven as a messenger."