From The Holy Quran
This is the Book in which there is no doubt. It is a guide for those who are God-conscious, who believe in the unseen, who establish prayer and spend in charity out of what We have provided for their sustenance; and who believe in this revelation (the Quran) that is sent to you (O Muhammad) and the revelations that were sent before you, and firmly believe in the Hereafter. They are on true guidance from their Lord, and they are the ones who will attain salvation." (2:2-5)
From Hadith:
On the authority of Abu Hurairah (ra) who said: The Messenger of Allah (saw), said: "Look upon one who is below you in status and do not look upon one who is above you in status. In this way you will not look down upon the grace that Allah has bestowed upon you." (Bukhari/Muslim)