THE FOUR NAMES OF A BOASTFUL PERSON.

Someone asked Rasulullah (sallallahu‐alayhi‐wa‐sallam) about which acts will secure salvation in the Hereafter. The reply was, "Do not deceive Allah." When the meaning of this was asked, Rasulullah (sallallahu‐alayhi‐wa‐sallam) said, "Act on Allah’s orders solely for Him, not for anyone besides Him. Performing an action for anyone besides Allah will be deceiving Him.
Guard against ostentation because this is shirk. The ostentatious person will be called by four names on the Day of Judgement (viz.) “Oh Kaafir!", “Oh Faajir” (Oh sinner!), “Oh Ghaadir” (Oh deceiver!), and “Oh Khaasir!” (Oh loser!). (Then they will be told,) “Your actions are wasted and your rewards spent. There is no share for you here and the deceiver should collect his reward from the one for whom he acted."
The Sahabi (R.A) who narrated this hadith swore by Allah that he heard this hadith from Rasulullah (sallallahu‐alayhi‐wasallam). Someone has said the following fine words, "Safeguarding an action is more difficult than performing it."