Riya'

Basically, the act of riya 'that is based on his intention in doing the deed worship that is addressed to other than Allah SWT. Because of intentions, others will not know that what it does is its purpose is to be praised. Therefore, it's good to recognize some things that mostly thought riya 'and shirk, but not. Riya 'is now so rampant. Although each person has a different level, the goal is to get the human praise and not be sincere. Riya 'is dangerous because it is one of the diseases of the heart that makes a person in the class of hypocrites.
Riya 'can happen to anyone even including the believer who is pious and shalehah though. In a hadith from Abu Hurairah RA, and narrated by Imam Muslim, Rasulullah SAW reported that the first group to be martyred was martyred, studying and teaching science, and giving charity.
Allah will throw all three into the fire of hell because the deeds of worship they do not with the intention to Allah SWT. Word of Allah SWT which means;
"And when they (the hypocrites) stand in prayer, they stand in laziness and riya 'before men and they do not remember Allah except very little." (Q. S. An Nisa verse 142).